CN114575976B

CN114575976B - System and method for mixing exhaust and reductant in an aftertreatment system

Info

Publication number: CN114575976B
Application number: CN202210283795.6A
Authority: CN
Inventors: 刘志立; A·卡艳卡; A·芒那纳; N·M·施密特; R·W·戴特拉; M·奇鲁塔
Original assignee: Cummins Emission Solutions Inc
Current assignee: Cummins Emission Solutions Inc
Priority date: 2017-06-06
Filing date: 2018-06-05
Publication date: 2023-10-27
Anticipated expiration: 2038-06-05
Also published as: GB2598500B; GB2598500A; BR112019025324A2; GB2602770A; US11136910B2; US11982219B2; GB202205057D0; WO2018226626A1; GB201917608D0; GB2602770B; CN109414661B; GB2577212A; CN114575976A; US20230108543A1; GB2577212B; US11542847B2; US20200123955A1; US20210372313A1; CN109414661A; DE112018002876T5

Abstract

The multistage mixer comprises a multistage mixer inlet, a multistage mixer outlet, a first flow device and a second flow device. The multi-stage mixer inlet is configured to receive exhaust gas. The multistage mixer outlet is configured to provide exhaust gas to the catalyst. The first flow device is configured to receive exhaust gas from the multi-stage mixer inlet and to receive a reductant such that the reductant is partially mixed with the exhaust gas in the first flow device. The first flow device includes a plurality of main vanes and a plurality of main vane orifices. The plurality of main vane apertures are spaced between the plurality of main vanes. The plurality of main vane apertures are configured to receive the exhaust gas and cooperate with the plurality of main vanes to provide a swirl to the gas from the first flow device row.

Description

System and method for mixing exhaust and reductant in an aftertreatment system

The application is a divisional application of the application application of which the application date is 2018, 6, 5, 201880001223.6 and the application name is 'a system and a method for mixing exhaust gas and reducing agent in an after-treatment system'.

Cross Reference to Related Applications

The present application claims the benefit of priority from U.S. provisional patent application No. 62/515,743 filed on 6/2017, the contents of which are incorporated herein by reference in their entirety.

Technical Field

The present application relates generally to the field of aftertreatment systems for internal combustion engines.

Background

For internal combustion engines, such as diesel engines, nitrogen oxide (NOx) compounds may be emitted in the exhaust. To reduce NOx emissions, selective Catalytic Reduction (SCR) processes may be employed to convert NOx compounds to more neutral compounds, such as diatomic nitrogen or water, via a catalyst and a reductant. Such catalysts may be contained in a catalyst chamber of an exhaust system, such as a catalytic chamber of a vehicle or power unit. A reducing agent, such as anhydrous ammonia, aqueous ammonia, diesel Exhaust Fluid (DEF), or aqueous urea solution, is typically introduced into the exhaust stream prior to the catalyst chamber. To introduce the reductant into the exhaust stream for the SCR process, the SCR system may inject or introduce the reductant through a dispensing module that evaporates or sprays the reductant into an exhaust conduit upstream of the exhaust system of the catalyst chamber. The SCR system may include one or more sensors to monitor conditions within the exhaust system.

Disclosure of Invention

In one embodiment, the multistage mixer comprises a multistage mixer inlet, a multistage mixer outlet, a first flow device and a second flow device. The multi-stage mixer inlet is configured to receive exhaust gas. The multistage mixer outlet is configured to provide exhaust gas to the catalyst. The first flow device is configured to receive exhaust gas from the multi-stage mixer inlet and to receive a reductant such that the reductant is partially mixed with the exhaust gas in the first flow device. The first flow device includes a plurality of main vanes and a plurality of main vane orifices. The plurality of main vane apertures are spaced between the plurality of main vanes. The plurality of main vane apertures are configured to receive the exhaust gas and cooperate with the plurality of main vanes to provide a swirling flow to the exhaust gas provided from the first flow device, the swirling flow facilitating mixing of the reductant with the exhaust gas. The second flow device is configured to receive the exhaust gas and the reductant from the first flow device. The second flow device includes a plurality of second flow device orifices configured to provide the exhaust gas and the reductant from the second flow device to a catalyst via a multi-stage mixer outlet.

In one embodiment, a multi-stage mixer includes a multi-stage mixer inlet, a multi-stage mixer outlet, and a first flow device. The multi-stage mixer inlet is configured to receive exhaust gas. The multistage mixer outlet is configured to provide exhaust gas to the catalyst. The first flow device is configured to receive exhaust gas from the multi-stage mixer inlet and configured to receive a reductant such that the reductant is partially mixed with the exhaust gas in the first flow device. The first flow device includes a venturi body, a plurality of primary vanes, a plurality of primary vane apertures, a plurality of auxiliary vanes, and a plurality of auxiliary vane apertures. The venturi body is defined by a body inlet proximate the multistage mixer inlet and a body outlet proximate the multistage mixer outlet. A plurality of main vanes are positioned within the venturi body proximate the body outlet. The plurality of main vane apertures are spaced between the plurality of main vanes. The plurality of main vane apertures are configured to receive the exhaust gas and cooperate with the plurality of main vanes to provide a swirling flow to the exhaust gas from the first flow device, the swirling flow facilitating mixing of the reductant with the exhaust gas. A plurality of auxiliary vanes are located within the venturi body proximate the body inlet. The plurality of auxiliary vane apertures are spaced between the plurality of main vanes. The plurality of auxiliary vane apertures are configured to receive the exhaust gas and cooperate with the plurality of auxiliary vanes to provide a swirling flow to the exhaust gas entering the venturi body, the swirling flow facilitating mixing of the reductant and the exhaust gas.

In another embodiment, a multi-stage mixer includes a multi-stage mixer inlet, a multi-stage mixer outlet, and a first flow device. The multi-stage mixer inlet is configured to receive exhaust gas. The multistage mixer outlet is configured to provide exhaust gas to the catalyst. The first flow device is configured to receive exhaust gas from the multi-stage mixer inlet and to receive a reductant such that the reductant is partially mixed with the exhaust gas in the first flow device. The first flow device includes a venturi body, a plurality of main vanes, a plurality of main vane orifices, and a plurality of exhaust guides. The venturi body is defined by a body inlet proximate the multistage mixer inlet and a body outlet proximate the multistage mixer outlet. The venturi body includes an exhaust gas directing orifice disposed along the venturi body between the body inlet and the body outlet. A plurality of main vanes are positioned within the venturi body proximate the body outlet. The plurality of main vane apertures are spaced between the plurality of main vanes. The plurality of main vane apertures are configured to receive the exhaust gas and cooperate with the plurality of main vanes to provide a swirling flow to the exhaust gas from the first flow device, the swirling flow facilitating mixing of the reductant with the exhaust gas. The exhaust guide is coupled to the venturi body about the exhaust guide aperture. The exhaust guide is configured to receive the exhaust gas and the reducing agent from outside the venturi body, respectively, mix the exhaust gas and the reducing agent received from outside the venturi body in the guide, and provide the mixed exhaust gas and reducing agent into the venturi body.

In another embodiment, a multi-stage mixer includes a multi-stage mixer inlet, a multi-stage mixer outlet, and a first flow device. The multi-stage mixer inlet is configured to receive exhaust gas. The multistage mixer outlet is configured to provide exhaust gas to the catalyst. The first flow device is configured to receive exhaust gas from the multi-stage mixer inlet and to receive a reductant such that the reductant is partially mixed with the exhaust gas in the first flow device. The first flow device includes a venturi body, a plurality of conduit straight vanes, and an exhaust guide. The venturi body is defined by a body inlet proximate the multistage mixer inlet and a body outlet proximate the multistage mixer outlet. The venturi body includes an exhaust gas directing orifice disposed along the venturi body between the body inlet and the body outlet. A plurality of conduit straight vanes are positioned within the venturi body proximate the body outlet. The plurality of conduit blades are configured to cooperate with the exhaust gas and provide a swirling flow to the exhaust gas from the first flow device that aids in mixing the reductant and the exhaust gas. The exhaust guide is coupled to the venturi body about the exhaust guide aperture. The exhaust guide is configured to receive exhaust gas and reductant from outside the venturi body, respectively, mix the exhaust gas and reductant received from outside the venturi body in the exhaust guide, and provide the mixed exhaust gas and reductant into the venturi body.

Drawings

The details of one or more implementations are set forth in the accompanying drawings and the description below. Other disclosed features, aspects, and advantages of the present disclosure will become apparent from the description, the drawings, and the claims, wherein:

FIG. 1 is a schematic block diagram of an exemplary selective catalytic reduction system having an exemplary reductant delivery system for an exhaust system; and

FIG. 2 is a cross-sectional view of an exemplary multistage mixer;

FIG. 3 is a cross-sectional view of another multi-stage mixer;

FIG. 4 is a cross-sectional view of yet another multi-stage mixer;

FIG. 5 is a cross-sectional view of yet another multi-stage mixer;

FIG. 6A is a cross-sectional view of another multi-stage mixer;

FIG. 6B is a front view of the flow device of the multistage mixer shown in FIG. 6A;

FIG. 6C is a front view of another flow device of the multistage mixer shown in FIG. 6A;

FIG. 7 is a representation of exhaust velocity streamlines within a multistage mixer;

FIG. 8 is a representation of reductant droplet distribution within a multistage mixer;

FIG. 9A is a front view of an exemplary flow device of a multistage mixer;

FIG. 9B is a front view of another flow device of the multistage mixer;

FIG. 9C is a front view of another flow device of the multistage mixer;

FIG. 9D is a front view of another flow device of the multistage mixer;

FIG. 9E is a front view of another flow device of the multistage mixer;

FIG. 9F is a front view of another flow device of the multistage mixer;

FIG. 9G is a front view of another flow device of the multistage mixer;

FIG. 10A is a cross-sectional view of an exhaust guide and a reductant guide for a multi-stage mixer;

FIG. 10B is a cross-sectional view of another exhaust guide and reductant guide for a multi-stage mixer;

FIG. 10C is a cross-sectional view of yet another exhaust guide for a multi-stage mixer;

FIG. 10D is a cross-sectional view of yet another exhaust guide for a multi-stage mixer;

FIG. 11A is a front view of yet another flow device of the multistage mixer;

FIG. 11B is a front view of yet another flow device of the multistage mixer;

FIG. 11C is a front view of yet another flow device of the multistage mixer;

FIG. 11D is a front view of yet another flow device of the multistage mixer;

FIG. 11E is a cross-sectional view of yet another multistage mixer;

FIG. 12A is a cross-sectional view of yet another multistage mixer;

FIG. 12B is a cross-sectional view of yet another multistage mixer;

FIG. 13 is a cross-sectional view of yet another multistage mixer;

FIG. 14 is a cross-sectional view of yet another multistage mixer;

FIG. 15 is a cross-sectional view of yet another multistage mixer;

FIG. 16 is a front view of a mixer of the multi-stage mixer;

FIG. 17 is a cross-sectional view of yet another multistage mixer;

FIG. 18A is a front view of another mixer of the multi-stage mixer;

FIG. 18B is a front view of another mixer of the multi-stage mixer;

FIG. 18C is a front view of another mixer of the multi-stage mixer;

FIG. 19 is a cross-sectional view of yet another multistage mixer;

FIG. 20 is a view of the downstream face of the multistage mixer;

FIG. 21 is a view of the upstream face of the multistage mixer;

FIG. 22A is a side view of yet another mixer of the other multi-stage mixer;

FIG. 22B is another side view of the mixer of FIG. 22A;

FIG. 23 is a bottom view of another mixer of the multi-stage mixer;

FIG. 24 is a side view of a portion of the mixer shown in FIG. 23;

FIG. 25 is a side view of a center hub for a multistage mixer;

FIG. 26 is a side view of the center hub shown in FIG. 25 with a plurality of blades;

FIG. 27 is a rear view of yet another flow device of the multistage mixer;

FIG. 28 is a rear view of yet another flow device of the multistage mixer;

FIG. 29 is a graph for analyzing normalized pressure drop and/or uniformity index associated with a flow device of a multi-stage mixer;

FIG. 30 is a rear view of yet another flow device of the multistage mixer;

FIG. 31 is a top view of another mixer of the multi-stage mixer;

FIG. 32 is a side cross-sectional view of the mixer shown in FIG. 31; and

fig. 33 is a side cross-sectional view of a multi-stage mixer including the mixer shown in fig. 31.

It should be appreciated that some or all of the figures are schematically represented for purposes of illustration. The drawings are provided for the purpose of illustrating one or more embodiments and are not to be construed as limiting the scope or meaning of the claims.

Detailed Description

The following is a more detailed description of various concepts and embodiments related to methods, apparatus and systems for flow distribution in an aftertreatment system. The various concepts introduced above and discussed in more detail below may be implemented in any of a variety of ways, as the described concepts are not limited to any particular implementation. Examples of specific implementations and applications are provided primarily for illustrative purposes.

I. Summary of the invention

Internal combustion engines (e.g., diesel engines, etc.) typically produce treated exhaust gas within an aftertreatment system. The treatment typically includes passing the exhaust through a catalyst. By providing a uniform exhaust flow to the catalyst, the efficiency of the catalyst, and thus the aftertreatment system, may be increased. Various components, such as baffles, may be included within the aftertreatment system to alter the flow of exhaust gas to the catalyst. Components implemented by conventional aftertreatment systems are difficult to scale (e.g., for different applications, etc.) in both radial (e.g., various diameters, etc.) and axial directions (e.g., various lengths of components, various numbers, various configurations of components). For example, the baffles may have complex shapes, which require advanced manufacturing techniques and are therefore costly to produce. As a result, conventional aftertreatment systems do not provide the flexibility necessary to facilitate implementation in applications having varying engine ratings and/or operating conditions. Furthermore, conventional aftertreatment systems typically use complex components that are expensive and require difficult and time-consuming fabrication.

Embodiments described herein relate to a multistage mixer that includes a plurality of flow devices that cooperate to provide a substantially uniform flow of exhaust gas and reductant for a catalyst, promote substantially uniform reductant distribution in the exhaust gas downstream of the multistage mixer, and provide a relatively low pressure drop (e.g., exhaust pressure at the inlet of the multistage mixer minus exhaust pressure at the outlet of the multistage mixer, etc.), all in a relatively compact space as compared to conventional aftertreatment systems. The flow devices are mostly symmetrical and relatively easy to manufacture compared to the complex devices currently used in aftertreatment systems. Thus, the multi-stage mixer may be simply and easily scaled for various applications while consuming less physical space than devices currently used in aftertreatment systems. The multi-stage mixer may be configured to distribute the exhaust gas with the reductant to create an internal swirl that mixes the reductant in the exhaust gas and creates a uniform reductant dispersion in a uniform exhaust gas flow flowing into the catalyst. Due to the swirling flow and the relatively high shear stresses created by the multi-stage mixer, the multi-stage mixer may minimize jet impingement (spray impingement) on the wall surface, thereby mitigating deposit formation and accumulation within the multi-stage mixer and associated exhaust components.

In some embodiments, the multi-stage mixer includes an exhaust gas guide that directs exhaust gas to the reductant injected from the reductant guide. Exhaust gas flows into the exhaust guide through an orifice provided on at least a portion of the exhaust guide. The exhaust gas then helps the reductant to enter the flow device, whereby the reductant and the exhaust gas may subsequently be mixed by swirling. Mixing may improve decomposition, enhance conventional and turbulent diffusion, and prolong the mixing trajectory of the exhaust gas and reductant by utilizing low pressure created by swirling and/or Venturi (Venturi) flow. Swirl refers to a flow that rotates about the central axis of the multistage mixer and/or the central axis of the flow device. Venturi flow refers to flow that occurs due to the reduced cross-sectional area and the low pressure region caused by local flow acceleration.

In some embodiments, the flow device of the multi-stage mixer includes an inner plate positioned below the reductant guide. When the reducing agent flows into the flow device, the reducing agent contacts the inner plate, which helps promote mixing of the reducing agent in the exhaust gas by reducing the stokes number of the reducing agent (e.g., reducing agent droplets, etc.) by splashing.

Post-processing System overview

FIG. 1 illustrates an aftertreatment system 100 having an exemplary reductant delivery system 110 for an exhaust system 190. The aftertreatment system 100 includes a particulate filter, such as a Diesel Particulate Filter (DPF) 102, a reductant delivery device 110, a decomposition chamber or reactor 104, an SCR catalytic chamber 106, and a sensor 150. In some embodiments, SCR catalyst 106 comprises an ammonia oxidation catalyst (ASC).

The DPF102 is configured to remove particulate matter, such as soot, from exhaust gas flowing within the exhaust system 190. The DPF102 includes an inlet that receives the exhaust gas and an outlet from which the exhaust gas exits after filtering and/or converting the particulate matter substantially from the exhaust gas to carbon dioxide. In some embodiments, the DPF102 may be omitted.

The decomposition chamber 104 is configured to convert a reducing agent, such as urea or DEF, to ammonia. Decomposition chamber 104 includes a reductant delivery apparatus 110 including a dispenser (doser) or dispensing module (dosing module) 112, dispensing module 112 configured to dispense reductant into decomposition chamber 104 (e.g., via an injector, such as the injector described below). In some embodiments, the reductant is injected upstream of SCR catalytic chamber 106. The reductant droplets then undergo processes of evaporation, pyrolysis, and hydrolysis to form gaseous ammonia in the exhaust system 190. The decomposition chamber 104 includes an inlet in fluid communication with the DPF102 to receive exhaust gas containing NOx emissions and an outlet for the exhaust gas, NOx emissions, ammonia, and/or reductant to flow to the SCR catalytic chamber 106.

Decomposition chamber 104 includes a dispensing module 112 mounted to decomposition chamber 104 such that dispensing module 112 may inject a reductant into the exhaust flowing within exhaust system 190. The dispensing module 112 may include insulation 114 interposed between a portion of the dispensing module 112 and a portion of the decomposition chamber 104 on which the dispensing module 112 is mounted. Dispensing module 112 is fluidly coupled to one or more reductant sources 116. In some embodiments, pump 118 may be used to pressurize reductant from reductant source 116 for delivery by dispensing module 112.

Dispensing module 112 and pump 118 may also be electrically or communicatively coupled to controller 120. The controller 120 is configured to control the dispensing module 112 to inject the reductant into the decomposition chamber 104. The controller 120 may also be configured to control the pump 118. The controller 120 may include a microprocessor, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or the like, or a combination thereof. The controller 120 may include memory including, but not limited to, any electronic, optical, magnetic, or any other storage or transmission device capable of providing program instructions to a processor, ASIC, FPGA, or the like. The memory may include a memory chip, an electrically erasable programmable read-only memory (EEPROM), an erasable programmable read-only memory (EPROM), a flash memory, or any other suitable memory from which the controller 120 may read instructions. The instructions may include code from any suitable programming language.

SCR catalytic chamber 106 is configured to help reduce NOx emissions by accelerating the NOx reduction process of ammonia and NOx in the exhaust gas to diatomic nitrogen and water. SCR catalytic chamber 106 includes an inlet in fluid communication with decomposition chamber 104 and an outlet in fluid communication with one end of exhaust system 190, receiving exhaust gas and reductant from the inlet.

The exhaust system 190 may further include an oxidation catalyst (e.g., a diesel oxidation catalyst chamber (DOC)) fluidly coupled to the exhaust system 190 (e.g., upstream of the SCR catalyst chamber 106 or the DPF 102) to oxidize hydrocarbons and carbon monoxide in the exhaust.

In some embodiments, the DPF102 may be located downstream of the decomposition chamber or reactor 104. For example, the DPF102 and the SCR catalyst 106 may be joined as a single unit. In some embodiments, the distribution module 112 may alternatively be located downstream or upstream of the turbocharger.

The sensor 150 may be coupled to the exhaust system 190 to detect a state of exhaust flowing through the exhaust system 190. In some embodiments, the sensor 150 has a portion disposed within the exhaust system 190, e.g., a tip of the sensor 150 extends into a portion of the exhaust system 190. In another embodiment, the sensor 150 may receive exhaust through another conduit (e.g., one or more sample tubes extending from the exhaust system 190). Although the sensor 150 is described as being located downstream of the SCR catalytic chamber 106, it should be understood that the sensor 150 may be located elsewhere in the exhaust system 190, including downstream of the DPF102, inside the DPF102, between the DPF102 and the decomposition chamber 104, inside the decomposition chamber 104, between the decomposition chamber 104 and the SCR catalytic chamber 106, inside the SCR catalytic chamber 106, or downstream of the SCR catalytic chamber 106. Further, two or more sensors 150 may be employed to detect the condition of the exhaust gas, such as two, three, four, five, or six sensors 150, each sensor 150 located at any of the aforementioned locations of the exhaust system.

Multistage Mixer examples

Fig. 2 depicts a multistage mixer 200 according to an exemplary embodiment. Although a multistage mixer 200 is described in a particular embodiment, it should be understood that the associated structures in this and similar embodiments may constitute other aftertreatment components, such asSCR catalysts, perforated pipes, tubes, manifolds, decomposition chambers or reactors, dispensers, dispensing modules or others. The multi-stage mixer 200 is configured to receive exhaust gas (e.g., combustion gases from an internal combustion engine, etc.) and provide a substantially uniform flow profile (e.g., flow profile, etc.) of the exhaust gas downstream. According to an exemplary embodiment, the multi-stage mixer 200 is additionally configured to treat the exhaust gas with a reducing agent (e.g., urea, diesel Exhaust Fluid (DEF),Etc.) to selectively dispense exhaust gases. Since the multi-stage mixer 200 provides a substantially uniform flow distribution of the exhaust gas and promotes mixing between the exhaust gas and the reductant, the multi-stage mixer 200 may also provide a substantially uniform reductant distribution downstream of the exhaust gas.

The multi-stage mixer 200 includes a multi-stage mixer inlet 202 and a multi-stage mixer outlet 204, the multi-stage mixer inlet 202 receiving exhaust gas entering the multi-stage mixer 200 and the multi-stage mixer outlet 204 providing exhaust gas from the multi-stage mixer 200. According to various embodiments, the multi-stage mixer inlet 202 receives exhaust gas from a diesel particulate filter (e.g., DPF102, etc.) and the multi-stage mixer outlet 204 provides the exhaust gas to the SCR catalyst 106.

The fluid flow may be defined by a Reynolds number and a Stokes number, the Reynolds number being related to the flow pattern of the fluid and the Stokes number being related to the properties of particles suspended in the fluid. Depending on the reynolds number, the fluid may be turbulent or laminar, for example. The flow of exhaust gas into the multistage mixer inlet 202 may be defined by a reynolds number that is greater than 104, indicating that the flow of exhaust gas is turbulent. Self-similarity exists because the flow of exhaust gas into the multistage mixer inlet 202 is turbulent. Depending on the stokes number, the particles may follow the fluid flow more or less. The reductant flow may be defined by a Stokes number, which is similar to one, indicating that the reductant is unlikely to follow the exhaust flow, which creates a problem in conventional mixing devices. Advantageously, the multi-stage mixer 200 includes various components and devices herein that cause the reductant to mix with the exhaust gas (e.g., by reducing the stokes number of the reductant, etc.) such that the reductant is propelled through the multi-stage mixer 200 along with the exhaust gas. In this manner, the multi-stage mixer 200 improves reductant mixing and reduces the risk associated with deposit formation in the multi-stage mixer 200. In various embodiments, the multi-stage mixer 200 is static and has no components that move through the multi-stage mixer 200 in response to the exhaust gases. In this way, the multi-stage mixer 200 may be less complex and less expensive to manufacture, and thus more satisfactory than aftertreatment elements having moving parts.

The multi-stage mixer 200 includes a plurality of flow devices that divide the multi-stage mixer 200 into a plurality of stages. Each of the plurality of flow devices is configured to vary the exhaust flow and the reductant such that the plurality of flow devices cumulatively achieve a target flow distribution for the exhaust at the multi-stage mixer outlet 204 and a target uniformity index (e.g., uniformity distribution, etc.) for the reductant. Obtaining a certain flow distribution and reductant homogeneity index is important in the operation of the aftertreatment system. For example, it is desirable to obtain a uniform flow distribution at the SCR catalyst inlet as well as a reductant uniformity index, as such flow distribution allows the SCR catalyst to obtain relatively high conversion efficiency.

As shown in fig. 2, the multi-stage mixer 200 includes a first flow device 206, a second flow device 208, a third flow device 210, and a fourth flow device 212. It should be appreciated that the multi-stage mixer 200 includes any combination of first flow devices 206, second flow devices 208, third flow devices 210, fourth flow devices 212, including combinations having a plurality of first flow devices 206, a plurality of second flow devices 208, a plurality of third flow devices 210, and/or a plurality of fourth flow devices 212, and combinations without first flow devices 206, second flow devices 208, third flow devices 210, and/or fourth flow devices 212.

When the exhaust enters the multi-stage mixer inlet 202, the exhaust is stage 0 before encountering the first flow device 206. At stage 0, the exhaust gas has not been affected by any flow means. The exhaust gas then flows through the first flow device 206. The first flow means 206 comprises a plurality of defined open areas a _I Is defined by the orifice N _I Through the opening area A _I The exhaust gas flows into the first stage. The orifice of the first flow device 206 is defined by an average area A _AI And (3) limiting. The first flow device 206 is configured to create a venturi flow, swirl, or mixing effect. The swirling effect may cause the multiple exhaust streams to be biased toward the periphery of the multi-stage mixer 200. The first flow device 206 may create a low pressure region at one stage. The low pressure region may promote enhanced reductant decomposition (e.g., by evaporation, by pyrolysis, etc.), conventional and turbulent diffusion, and reductant droplet mixing. The low pressure region may also draw exhaust flow and reductant from the periphery of first flow device 206 to first flow device 206.

The exhaust then flows through the second flow device 208. The second flow means 208 comprises a plurality of defined open areas a _II Is defined by the orifice N _II Through the opening area A _II The exhaust gas flows into the second stage. The orifice of the second flow device 208 is defined by an average area A _AII And (3) limiting. The exhaust gas then flows through the third flow device 210. The third flow means 210 comprises a plurality of defined open areas a _III Is defined by the orifice N _III Through the opening area A _III The exhaust gas flows into three stages. The orifices of the third flow device 210 are defined by an average area A _AIII And (3) limiting. The exhaust gas then flows through the fourth flow device 212. The fourth flow means 212 comprises a plurality of defined open areas a _IV Is defined by the orifice N _IV Through the opening area A _IV The exhaust gas flows into the four stages. The orifice of the fourth flow device 212 is defined by an average area A _AIV And (3) limiting. The fourth flow device 212 may include a perforated plate that is uniform or otherwise patterned with a _AIV Relatively small. In this manner, fourth flow device 212 may be configured to provide exhaust gas to the fourth stage in a uniform flow and reductant distribution. From the four stages, the exhaust gas flows out of the multi-stage mixer outlet 204 of the multi-stage mixer 200.

According to an example embodiment, the multistage mixer 200 is configured to:

A _I ≈A _II ≈A _III ≈A _IV (1)

A _AI ≠A _AII ≠A _AIII ≠A _AIV (2)

N _I ≠N _II ≠N _III ≠N _IV (3)

this allows the exhaust dynamic pressure to remain substantially the same at each of the zero, first, second, third, and fourth stages. In various embodiments, the first flow device 206, the second flow device 208, the third flow device 210, and the fourth flow device 212 are each configured to:

A _AI ＞A _AII ＞A _AIII ＞A _AIV (4)

N _I ＜N _II ＜N _III ＜N _IV (5)

this facilitates a gradual change in exhaust flow by minimizing exhaust pressure drop. The exhaust pressure drop is calculated (e.g., determined) by subtracting the exhaust pressure of the multi-stage mixer outlet 204 from the exhaust pressure of the multi-stage mixer inlet 202. In various embodiments, the multistage mixer 200 is configured to reduce pressure drop as compared to conventional aftertreatment systems when the associated internal combustion engine is operating in a transient cycle (e.g., federal test procedure, world-coordinated transient cycle, off-highway transient cycle, etc.), steady state cycle (e.g., world-coordinated stationary cycle, etc.), or a combination thereof.

The multistage mixer 200 includes a dispenser 214 and a port 216 through which reductant (e.g., reductant droplets, etc.) is selectively introduced from the dispenser 214 to the multistage mixer 200. According to an exemplary embodiment, the dispenser 214 is located within the zero order. The multi-stage mixer 200 uniformly disperses the reductant in the exhaust gas flowing from the multi-stage mixer outlet 204 of the multi-stage mixer 200. The ports 216 are configured to direct, or help direct, the reductant toward a center (e.g., a center axis, a center of a domain, etc.) of the multi-stage mixer 200 regardless of conditions (e.g., flow rate, temperature, etc.) of the exhaust. For example, the ports 216 may have a variety of shapes and/or thicknesses to direct the reducing agent toward the center of the multi-stage mixer 200.

In some embodiments, the multi-stage mixer 200 also includes a reductant guide 218 (e.g., a nozzle, a perforated tube) that at least partially protects the reductant in the exhaust stream from the multi-stage mixer inlet 202 so as to direct the reductant to the center of the multi-stage mixer 200. A reductant guide 218 extends from the port 216, receives reductant from the dispenser 214, and provides reductant into the multi-stage mixer 200 (e.g., at a center of the multi-stage mixer 200, etc.). In various embodiments, reductant guide 218 is frustoconical.

In one embodiment, the first flow device 206, the second flow device 208, the third flow device 210, and the fourth flow device 212 are symmetrical. Thus, the manufacture of the first flow device 206, the second flow device 208, the third flow device 210, the fourth flow device 212 is simplified, and the dimensions of the first flow device 206, the second flow device 208, the third flow device 210, the fourth flow device 212 may be easily changed for various applications. In contrast, conventional aftertreatment devices typically include asymmetric components that are in contact with the flow. Therefore, the multistage mixer 200 is more ideal than a conventional aftertreatment device. Thus, any of the first flow device 206, the second flow device 208, the third flow device 210, and the fourth flow device 212 may be easily replaced with additional flow devices so that the multi-stage mixer 200 may be customized for a target application.

Due to the particular configuration and construction of the multi-stage mixer 200, the multi-stage mixer 200 is scalable and simply configurable while maintaining the ability to provide exhaust gas with highly uniform flow and reductant distribution while minimizing the pressure drop experienced by the exhaust gas and minimizing the likelihood of deposit (e.g., urea deposit, etc.) formation. Accordingly, the multi-stage mixer 200 can be configured for a target application (i.e., due to scalability and modularity of the multi-stage mixer 200, etc.) at a lower cost than other mixers that are not readily adaptable. The multi-stage mixer 200 and its components are expandable in both the axial direction (e.g., length, etc.) and the radial direction (e.g., diameter, etc.). For example, the multi-stage mixer 200 may be scaled to include additional or fewer flow devices. In an embodiment, the multistage mixer 200 may be scaled by including additional flow devices.

Through scaling, the multi-stage mixer 200 may be used in a variety of applications requiring different lengths and/or diameters of the multi-stage mixer 200. For example, a multi-stage mixer may be produced for use with an after-treatment system of a marine vessel of one size and a diesel commercial vehicle of another size.

Due to the flexibility of the multi-stage mixer 200, the multi-stage mixer 200 can be manufactured at a lower cost than conventional aftertreatment devices and can be easily adapted to many specific applications, thereby manufacturing a multi-stage mixer that is more satisfactory than conventional aftertreatment devices. Further, the multistage mixer 200 may be configured for retrofit or plug-in applications.

Although the multi-stage mixer 200 is shown as including the first flow device 206, the second flow device 208, the third flow device 210, and the fourth flow device 212, it should be understood that the multi-stage mixer 200 may include more or less flow devices, such that the multi-stage mixer 200 is suitable for the target application. Further, the number, shape, and size of the apertures in any of the first flow device 206, the second flow device 208, the third flow device 210, and the fourth flow device 212 may be varied so that the multi-stage mixer 200 may be customized for a target application. In some applications, the number of flow devices and their configuration may be tailored to improve reductant decomposition, exhaust gas distribution, reductant distribution within the exhaust gas, and to minimize pressure drop of the exhaust gas.

Fig. 3 illustrates a multistage mixer 200 according to an embodiment. The multi-stage mixer 200 includes a first flow device 206, a second flow device 208, and a third flow device 210. The first flow device 206 is shown to include a funnel rim 300, a venturi body 302, and a first support flange 304 (e.g., a downstream support flange, etc.). The funnel rim 300 is continuous with the venturi body 302, and the venturi body 302 is continuous with the first support flange 304. The funnel rim 300 is configured to direct a majority of the exhaust gas from the multi-stage mixer inlet 202 into the venturi body 302. However, the funnel rim 300 allows a portion of the exhaust gas to initially bypass the venturi body 302 and enter the region between the first flow device 206 and the multi-stage mixer 200. The funnel edge 300 may have various angles (e.g., 90 °, 45 °, 30 °, 15 °, etc.) with respect to the central axis of the multistage mixer 200. In addition, the funnel edge 300 may have various heights relative to an outer edge of the body (e.g., relative to an outer diameter of the body, etc.), as will be explained in more detail herein. By adjusting the height of the funnel edge 300, more or less exhaust gas may be directed into the first flow device 206 and more or less exhaust gas may be directed around the first flow device 206 (e.g., in a bypass flow manner).

The venturi body 302 may be circular, conical, frustoconical, streamlined, or other similar shape. The first support flange 304 is used to couple the first flow device 206 to the multi-stage mixer 200. In various embodiments, the first support flange 304 provides a seal between the venturi body 302 and the multi-stage mixer 200 such that no exhaust gas may pass through or around the first support flange 304. Thus, the exhaust gas is redirected from the upstream first support flange 304 to enter the venturi body 302. However, as described in more detail herein, in some embodiments, the first support flange 304 has an aperture through which exhaust gas may pass through the first flow device 206.

As shown in fig. 3, the first flow device 206 includes an exhaust guide orifice 306 and an exhaust guide 307, the exhaust guide 307 being coupled with the port 216. The exhaust guide 307 is frustoconical. The exhaust guide 307 receives reductant from the dispenser 214 (not shown in fig. 3), through the port 216, and flows the reductant into the venturi body 302. The exhaust guide 307 is coupled with the venturi body 302 of the first flow device 206 around the exhaust guide orifice 306 or integrated within the venturi body 302 of the first flow device 206 such that exhaust cannot flow between the exhaust guide 307 and the venturi body 302. In contrast, the exhaust guide 307 includes a plurality of apertures 308, each of which receives exhaust gas and directs the exhaust gas into the exhaust guide 307. The exhaust gas is then mixed with reductant from the venturi body 302 and/or the dispenser 214 within the exhaust guide 307. The flow of exhaust gas into the exhaust gas guide 307 causes the reductant from the dispenser 214 to flow with the exhaust gas into the venturi body 302 and toward the center of the multi-stage mixer 200. In this way, the flow of reductant is assisted by the exhaust gas flow.

According to various embodiments, reductant guide 218 is positioned within exhaust guide 307. In these embodiments, the reductant is separated from the exhaust gas until the reductant exits the reductant guide 218, at which point the exhaust gas advances the reductant toward the center of the multi-stage mixer 200. By initially separating the reductant and the exhaust gas, accumulation of the reductant within the multi-stage mixer 200 may be minimized by minimizing impingement on the injection wall of the multi-stage mixer 200.

According to various embodiments, the diameter of the venturi body 302 is:

0.25D ₀ ≤D _C ≤0.9D ₀ (6)

wherein the venturi body 302 is defined by a diameter DC and the multi-stage mixer 200 is defined by an inner diameter D0 that is greater than DC. The static pressure measured at the venturi body 302 is given by

Wherein P is _C Is the absolute static pressure at the venturi body 302, where P ₀ Is the absolute static pressure upstream of the venturi body 302 (e.g., measured by a pressure sensor, measured by a sensor, etc.), where ρ is the exhaust gas density, where v ₀ Is the flow rate upstream of the venturi body 302 (e.g., as measured by a sensor, etc.). The venturi body 302 forms a low pressure region due to the difference in diameter between the venturi body 302 and the multi-stage mixer 200. The low pressure region may facilitate enhancing (e.g., increasing, accelerating, etc.) decomposition of the reductant (e.g., by evaporation, by pyrolysis, etc.), conventional and turbulent diffusion, and reductant droplet mixing.

In some embodiments, the first flow device 206 further includes a main mixer 309, the main mixer 309 having a plurality of main vanes 310 and a plurality of main vane apertures 312 spaced therebetween to provide swirl flow, thereby creating additional low pressure regions and promoting mixing by extending the mixing trajectory of the first flow device 206. The primary vanes 310 are attached to and conform to the venturi body 302 such that exhaust gas can only exit the venturi body 302 through the primary vane apertures 312. The main blades 310 are also attached to and conform with a main blade center hub 313, the main blade center hub 313 being centered about the central axis of the venturi body 302.

The main vane 310 is stationary and does not move within the venturi body 302. In this way, the fabrication of the main mixer 309 may be less complex and less expensive, and thus more desirable than aftertreatment components having complex components that are expensive and require difficult and time-intensive fabrication. Rather than restricting the exhaust flow in a single path to create a swirl, the main vanes 310 provide several openings between adjacent main vanes 310 such that each main vane 310 independently rotates the exhaust and such that the main vanes 310 collectively form a swirl in the exhaust.

The main vane 310 is positioned (e.g., curved, angled, bent, etc.) to induce a swirling (e.g., mixing, etc.) flow of the exhaust gas and the reductant to form a mixture. In various embodiments, the main blade 310 is substantially straight (e.g., disposed substantially along a plane, having a substantially constant slope along the main blade 310, etc.). In other embodiments, the main blade 310 is curved (e.g., not substantially disposed along a plane, having a different slope along the main blade 310, having a curved edge relative to the remainder of the main blade 310, etc.). In other embodiments, adjacent main blades 310 are positioned to extend from each other. In these embodiments, the main blade 310 may be straight and/or curved. In embodiments having multiple master blades 310, each master blade 310 may be configured independently such that the master blade 310 is individually customized to achieve the target configuration of the first flow device 206 such that the multi-stage mixer 200 is customized for the target application.

Each primary blade 310 is defined by a blade angle (e.g., relative to a central axis of the multi-stage mixer 200, etc.) that is related to the vortex created by the primary blade 310. The blade angle of each main blade 310 may be different from the blade angle of any other main blade 310. According to various embodiments, the first flow device 206 includes a main vane 310, the main vane 310 having a vane angle between 30 ° and 80 °. However, the main blade 310 may have other suitable blade angles. Similarly, the first flow device 206 may include any number of primary vanes 310. In some embodiments, first flow device 206 includes four to twelve main vanes 310.

The main vane apertures 312 collectively define an open area A _I . However, the mainThe size of the blade apertures 312 is partially related to the diameter of the main blade center hub 313. According to various embodiments, the diameter of the main blade center hub 313 is given by

0.05D _C ≤D _H ≤0.25D _C (8)

Wherein D is _H Is the diameter of the main blade center hub 313. In application, the number in the main blades 310, the blade angle of the main blades 310, and the diameter of the main blade center hub 313 may be arbitrarily changed to optimize improvements in exhaust gas flow and reductant flow, improvements in reductant mixing, and improvements in minimizing pressure drop. The main mixer 309 may be configured such that the main blades 310 are symmetrically or asymmetrically disposed about the main blade center hub 313.

The second flow device 208 shown in fig. 3 includes a second flow device central aperture 314 and a plurality of second flow device apertures 316. The second flow device central aperture 314 is aligned with the center of the first flow device 206 and/or with the center of the multi-stage mixer 200 and is surrounded by a plurality of second flow device apertures 316. In operation, exhaust gas flows through main vane orifice 312 and into the first stage, along with reductant, and then flows through second flow device center orifice 314 and second flow device orifice 316 and into the second stage. The second flow device central aperture 314 and the second flow device aperture 316 collectively define an opening area a _II 。

The swirling flow created by the main vanes 310 may cause the multiple exhaust and reductant flows to be biased toward the periphery of the multi-stage mixer 200. The second flow device center aperture 314 and the second flow device aperture 316 may counteract this bias by creating a relatively low flow restriction centrally through the second flow device center aperture 314 and a relatively large flow restriction through the second flow device aperture 316 near the perimeter of the multi-stage mixer 200. This interaction between the first flow device 206 and the second flow device 208 improves the flow and uniformity of the exhaust and reductant while continuing to minimize pressure drop.

The third flow device 210 shown in fig. 3 includes a plurality of third flow device orifices 318. The plurality of third flow device orifices 318 may be substantially similar to the second flow device orifice 316.In operation, exhaust gas flows with reductant through second flow device central aperture 314 and second flow device aperture 316 and into the second stage, and then through third flow device aperture 318 and into the third stage. The third flow device orifices 318 collectively define an open area A _III . From the third stage, the exhaust gas exits the multi-stage mixer 200 through the multi-stage mixer outlet 204 along with the reductant.

The third flow device orifices 318 may be identical to each other and evenly spaced along the third flow device 210. In this manner, third flow device 210 may provide a substantially uniform flow and distribution of exhaust and reductant. In this manner, the third flow device 210 may reduce or eliminate shear experienced downstream of the multi-stage mixer 200, such as at the inlet of the SCR catalyst 106, which minimizes erosion, such as that typically experienced by catalyst materials that entrain hard aerosol particles in a rotating exhaust stream due to contact.

Fig. 4 shows a multistage mixer 200 according to another embodiment. As shown in fig. 4, the angle of the funnel-shaped edge 300 of the first flow means 206 is smaller than the angle of the funnel-shaped edge 300 shown in fig. 3. Thus, a greater amount of exhaust gas may flow between the venturi body 302 and the multi-stage mixer 200 in the multi-stage mixer 200 shown in fig. 4 than in the multi-stage mixer 200 shown in fig. 3. Further, the multi-stage mixer 200 shown in fig. 4 does not include the exhaust guide 307 or the reducing agent guide 218 in the multi-stage mixer 200 as shown in fig. 3. And reductant is output from the dispenser 214 (not shown in fig. 4) through the port 216 and into the venturi body 302 through the exhaust guide aperture 306. The reductant guide 218 may be coupled to the venturi body 302 around the exhaust guide aperture 306 such that no exhaust gas flows between the cylindrical body and the reductant guide 218. In this way, the reductant is mixed with the exhaust gas within the venturi body 302. Alternatively, a gap may exist between the reductant guide 218 and the venturi body 302 such that the reductant flows into the region between the venturi body 302 and the multi-stage mixer 200 and mixes with the exhaust gas there. From there, exhaust and reductant may flow into the venturi body 302 through the exhaust guide orifice 306.

As shown in fig. 4, the first flow device 206 further includes a plurality of inner plates 400 disposed along the venturi body 302. After the reductant enters the venturi body 302 via the exhaust guide aperture 306, the reductant falls into the venturi body 302 and may contact any inner plate 400. Contact between the inner plate 400 and the reductant helps to direct the reductant along a target trajectory before reaching the main mixer 309, the second flow device 208, the third flow device 210, or any other downstream component or part of the multi-stage mixer 200. In this manner, the inner plate 400 provides a suitable degree of premixing to improve the uniformity index of the exhaust (e.g., spatial distribution of reductant relative to NOx in the exhaust, etc.). Additionally, the inner plate 400 may help reduce the droplet size of the reductant, thereby reducing the stokes number of the reductant, which increases the ability of the reductant to mix with the exhaust gas. In this way, the inner plate helps to improve the proportionality variability (scalability) of the multistage mixer 200. The number, shape, size, angle (e.g., blade angle, etc.) and configuration of the inner plates 400 may be varied such that the multi-stage mixer 200 achieves relatively uniform exhaust gas flow and reductant flow and relatively uniform reductant distribution in the exhaust gas while minimizing jet impingement on the walls of the multi-stage mixer.

Although the plurality of inner plates 400 are only shown in fig. 4 herein, it should be understood that all embodiments of the multi-stage mixer 200 may include a plurality of inner plates 400 in any of the first flow devices 206, second flow devices 208, third flow devices 210, and fourth flow devices described herein.

Fig. 5 shows a multistage mixer 200 according to another embodiment. As shown in fig. 5, the exhaust gas flows into the venturi body 302 of the first flow device 206 and the reductant is introduced into the venturi body 302 via the exhaust guide orifice 306 and the reductant guide 218 (not shown), which reductant guide 218 extends into the exhaust guide 307. In some embodiments, the exhaust guide 307 is coupled to the multi-stage mixer 200 or integrated within the multi-stage mixer 200. In other embodiments, the exhaust guide 307 is spaced apart from the multi-stage mixer 200 such that exhaust gas may flow between the exhaust guide 307 and the walls of the multi-stage mixer 200. Drawing of the figureThe first flow device 206 shown in fig. 5 does not include the main mixer 309 shown in fig. 3 and 4. Instead, the exhaust and reductant flow directly from the interior of the venturi body 302 into one stage and then through the second flow device orifice 316 in the second flow device 208. In this manner, the venturi body 302 defines an open area A _I 。

Although the second flow device 208 does not include the second flow device central aperture 314 shown in fig. 3, the second flow device aperture 316 shown in fig. 5 is larger than the second flow device aperture 316 shown in fig. 1. Thus, the second flow device orifice 316 shown in FIG. 2 defines an opening area A _II Which is substantially equal to the open area a of the first flow means 206 _I . As shown in fig. 5, the third flow device 210 includes a third flow device central aperture 500. Exhaust and reductant flow from the second flow device orifice 316 into the second flow device 208 into the second stage and then through the third flow device 210 through the third flow device orifice 500 into the third stage. The third flow device central aperture 500 defines an opening area a _III . From three stages, the exhaust and reductant flow through a plurality of fourth flow device apertures 502 in fourth flow device 212. The fourth flow device orifice 502 may be a plurality of perforations. Fourth flow device orifice 502 defines an opening area A _IV . From stage four, the exhaust and reductant flow out of the multi-stage mixer 200 through the multi-stage mixer outlet 204.

Fig. 6A-6C illustrate a multistage mixer 200 and its components according to another embodiment. As shown in fig. 6A, both the first flow device 206 and the third flow device 210 replace the fifth flow device 600. The fifth flow device 600 includes a fifth flow device central aperture 602. Further, the fifth flow device 600 does not include the funnel shaped rim 300, the venturi body 302, or the exhaust guide aperture 306. The exhaust gas flows into the multistage mixer 200, and the reducing agent is introduced into the exhaust gas via the exhaust guide 307. The exhaust gas and reductant together flow through a fifth flow device central aperture 602 in the fifth flow device 600 and into the stage. As shown in fig. 6B, the fifth flow device central aperture 602 may be centrally disposed within the fifth flow device 600. In this manner, the fifth flow device central aperture 602 defines an opening area a _I . From one stage, the exhaust and reductant flow through a second flow device orifice 316 in the second flow device 208 from the one stage and into the second stage. As shown in fig. 6C, the second flow device orifices 316 may be identical and evenly circumferentially disposed about the central axis of the second flow device 208. From the second stage, exhaust and reductant flow from the second stage through a fifth flow device central aperture 602 in the fifth flow device 600 and into the third stage. In this manner, the fifth flow device central aperture 602 defines an opening area a _III Which is equal to the opening area A _I . From the third stage, the exhaust and reductant flow through the fourth flow device orifice 502 and into the fourth stage.

FIG. 7 illustrates the exhaust gas flow line velocity and the potential reductant velocity within the multi-stage mixer 200 including the first flow device 206, the second flow device 208, and the third flow device 210. Fig. 7 was generated using a simulation with an absolute pressure change of 521 pascals at a mass flow rate of 8.5 kilograms per minute and 335 ℃. As shown in fig. 7, the flow line enters the multistage mixer 200 relatively straight, swirl is imparted by the first flow device 206, and then straightened by the second flow device 208 and the third flow device 210 until the flow line is relatively straight before exiting the multistage mixer.

Fig. 8 illustrates the locations of reductant droplets and their corresponding dimensions within the multi-stage mixer 200 including the first flow device 206, the second flow device 208, the third flow device 210, and the port 216. As shown in fig. 8, the reductant droplets enter the multistage mixer 200, swirl is imparted by the first flow device 206, and then are uniformly dispersed by the second flow device 208 and the third flow device 210 until the reductant droplets are relatively uniformly dispersed before exiting the multistage mixer 200.

Fig. 9A-9G illustrate a sixth flow device 900 according to various embodiments. The sixth flow device 900 may be any of the first flow device 206, the second flow device 208, the third flow device 210, the fourth flow device 212, and the fifth flow device 600 as described herein.

The sixth flow device 900 includes a plurality of sixth flow device orifices 902. By increasing the size of the sixth flow device orifice 902 within the sixth flow device 900, the flow of exhaust and reductant may become more uniform, and the distribution of reductant within the exhaust may also become more uniform. These same benefits may be achieved by increasing the density of sixth flow device orifice 902 proximate sixth flow device 900.

In other applications, the sixth flow device orifices 902 may be evenly distributed around the central region 904, as shown in fig. 9D. The central region 904 may include additional sixth flow device orifices 902 that are uniformly distributed within the central region 904. As shown in fig. 9D, the sixth flow device 900 is configured such that the sixth flow device orifice 902 that is not disposed within the central region 904 is more sparse than the sixth flow device orifice 902 that is disposed within the central region 904.

As shown in fig. 9A, sixth flow device orifices 902 are evenly distributed through sixth flow device 900 and are identical to sixth flow device orifices 902. In this manner, the flow generated by sixth flow device 900 may be substantially uniform. This arrangement of the sixth flow device 900 may be implemented near the multi-stage mixer outlet 204 of the multi-stage mixer 200.

However, the sixth flow device orifice 902 may also have a different size, and the sixth flow device orifice 902 may be arranged according to its size. As shown in fig. 9B and 9C, sixth flow device orifices 902 are evenly distributed through sixth flow device 900, with larger sixth flow device orifices 902 being disposed near the center of sixth flow device 900 and smaller sixth flow device orifices 902 being disposed near the periphery of sixth flow device 900. This arrangement of the sixth flow device 900 may be implemented after the vortex is formed (e.g., at the first flow device 206, etc.).

In other applications, the sixth flow device orifices 902 may be evenly distributed around the central region 904. The central region 904 may include additional sixth flow device orifices 902 that are uniformly distributed within the central region 904. As shown in fig. 9D, the sixth flow device 900 is configured such that the sixth flow device orifice 902 that is not disposed within the central region 904 is more sparse than the sixth flow device orifice 902 that is disposed within the central region 904. In still other applications, the sixth flow device apertures 902 may be evenly distributed around the central aperture 906. As shown in fig. 9E, the sixth flow device 900 is configured such that the sixth flow device apertures 902 are evenly disposed about the central aperture 906.

In some applications, each of the sixth flow device apertures 902 includes a sixth flow device vane 908 adjacent to the sixth flow device aperture 902. As shown in fig. 9F, the sixth flow device orifice 902 is semi-circular and the sixth flow device vane 908 is semi-circular. As shown in fig. 9G, the sixth flow device orifice 902 is square and the sixth flow device vane 908 is square. In fabrication, the sixth flow device orifice 902 and the sixth flow device vane 908 may be formed simultaneously (e.g., by a punch, die, etc.).

The sixth flow device vane 908 may be configured to flow exhaust and reductant in a target direction. The sixth flow device apertures 902 and the sixth flow device vanes 908 may be arranged in a plurality of rows and columns across the sixth flow device 900. As shown in fig. 9F and 9G, the direction of the sixth flow device blades 908 may alternate within a row and be the same within a column. However, other arrangements and configurations of the sixth flow device vane 908 and the sixth flow device orifice 902 are also possible. For example, the sixth flow device vane 908 and the sixth flow device aperture 902 may cooperate to create a swirl flow.

10A-10D illustrate the exhaust guide 307 in more detail, according to various embodiments. It should be appreciated that the exhaust guide 307 shown and described with reference to fig. 10A-10D may be included in any of the embodiments of the multi-stage mixer 200 described herein.

As shown in fig. 10A and 10B, the reducing agent guide 218 is located within the exhaust guide 307. The reductant guide 218 is configured to pass the reductant through the exhaust guide 307 and into the multi-stage mixer 200. The exhaust guide 307 is defined by a first angle (e.g., at a vertex, etc.), and the multi-stage mixer 200 is defined by a second angle (e.g., at a vertex, etc.) that is less than the first angle. In this manner, the exhaust guide 307 and the multi-stage mixer 200 are configured to minimize jet impingement on the exhaust guide 307.

An orifice 308 is positioned along exhaust guide 307 and is configured to direct exhaust gas into an area between exhaust guide 307 and reductant guide 218 such that the exhaust gas is directed out of nozzle 1000 of exhaust guide 307. The reductant from the reductant guide 218 may be entrained in the exhaust gas to be ejected from the exhaust guide 307 together with the exhaust gas. As shown in fig. 10A, the aperture 308 is disposed along a front surface 1002 of the exhaust guide 307. The front surface 1002 is adjacent to the exhaust flow from the multi-stage mixer inlet 202 (e.g., upstream, etc.) of the multi-stage mixer 200. The front surface 1002 may be defined by an angular section of the exhaust guide 307. For example, the front surface 1002 may be approximately 120 degrees of the exhaust guide 307, centered on the direction of exhaust flow into the exhaust guide 307.

The apertures 308 may have different shapes, sizes, pitches, densities, and configurations. The apertures 308 may, for example, be configured to direct exhaust gas out of the nozzle 1000 in a vertical direction (e.g., relative to the flow of exhaust gas into the multi-stage mixer inlet 202). For example, as shown in fig. 10B, the orifices 308 are uniformly arranged along the exhaust guide 307. In another example shown in fig. 10C, apertures 308 are provided along front surface 1002. However, as shown in fig. 10C, the exhaust guide 307 includes a cylindrical section 1006 that does not include any apertures 308. The cylindrical cross section 1006 may facilitate use of the exhaust guide 307 in space-limited applications. Further, as shown in fig. 10D, the exhaust guide 307 includes a deformed section 1008, which deformed section 1008 also facilitates use of the exhaust guide 307 in space-limited applications.

Fig. 11A-11E illustrate a portion of a first flow device 206 in accordance with various embodiments. In some embodiments, the primary mixer 309 includes a complementary blade 1100 positioned on each primary blade 310. It should be appreciated that the complementary blades 1100 shown and described with reference to fig. 11A-11E may be included in any of the embodiments of the multistage mixer 200 discussed herein.

Complementary vane 1100 defines a complementary aperture 1102 adjacent main vane aperture 312. In this way, the complementary vane 1100 increases the opening area AI of the first flow device 206. The complementary blade 1100 may be configured at various angles relative to the main blade 310, and in various shapes, sizes, and configurations. For example, the first flow device 206 may be configured with some primary vanes 310 that include complementary vanes 1100, and other primary vanes 310 that do not include complementary vanes 1100.

The complementary blades 1100 may be positioned adjacent to the edge of each main blade 310, as shown in fig. 11A and 11D, or within the main blade 310, as shown in fig. 11B and 11C. In addition, the complementary vanes 1100 may be configured to generate a swirl (e.g., co-swirl, anti-swirl, etc.) that is separate from the swirl generated by the main vane 310. In this manner, the complementary vanes 1100 may be used to increase or decrease the total vortex created by the first flow device 206. In some embodiments, multi-stage mixing may be achieved in the axial direction by using two flow devices (e.g., first flow device 206, second flow device 208, etc.) that include complementary blades 1100.

Fig. 11E shows a cross-sectional view of the multistage mixer 200 including the first flow device 206, including the complementary blades 1100. In the present embodiment, the auxiliary mixer 1106 is omitted. In some multi-stage mixer 200 applications, the auxiliary mixer 1106 may not be needed and may be omitted to reduce the cost and manufacturing complexity of the multi-stage mixer 200. For example, when the multi-stage mixer 200 is placed downstream of the turbocharger in a close-coupled arrangement (e.g., the multi-stage mixer 200 is placed in close proximity to the turbocharger outlet, etc.), the auxiliary mixer 1106 may not be included in the multi-stage mixer 200 because the turbocharger generates a relatively high swirl velocity at the multi-stage mixer inlet 202.

As shown in fig. 12A-B, the first flow device 206 includes an auxiliary mixer 1106, the auxiliary mixer 1106 including auxiliary vanes 1108. It should be appreciated that the auxiliary mixer 1106 shown and described with respect to fig. 12A may be included in any of the embodiments of the multistage mixer 200 discussed herein.

The auxiliary blades 1108 are attached to an auxiliary blade center hub 1109, which auxiliary blade center hub 1109 is located on the center shaft of the multistage mixer 200. The auxiliary vane center hub 1109 is coupled to the venturi body 302 (e.g., by spacing members of adjacent auxiliary vanes 1108, etc.). The auxiliary mixer 1106 is configured to receive the exhaust gas from the multi-stage mixer inlet 202 and provide the exhaust gas to the venturi body 302. The auxiliary blade 1108 may be similar or different from the main blade 310. The tip (e.g., outermost surface, etc.) of each auxiliary vane 1108 may be spaced apart from the venturi body 302 by an air gap so that exhaust may pass between the tip of each auxiliary vane 1108 and the venturi body 302.

The auxiliary mixer 1106 includes a plurality of auxiliary vane apertures 1110 spaced between a plurality of auxiliary vanes 1108. In this manner, the plurality of auxiliary vanes and the plurality of auxiliary vane apertures 1110 provide swirl in the first flow device 206. The plurality of auxiliary vane apertures 1110 cooperate with the plurality of auxiliary vanes 1108 to provide exhaust gas to the first flow device 206 with swirling flow to promote mixing of the reductant and the exhaust gas. The auxiliary vanes 1108 may be configured to generate a swirl (e.g., co-swirl, anti-swirl, etc.) that is separate from the swirl generated by the main vane 310 and/or the complementary vane 1100. In this manner, the auxiliary vane 1108 may be used to increase or decrease the total vortex created by the first flow device 206. Further, the auxiliary vanes 1108 may increase mixing of the exhaust gas between the reductant and the venturi body 302.

In another example shown in FIG. 12A, the auxiliary vane 1108 is located upstream of the location where the reductant is introduced, and the complementary vane 1100 and the main vane 310 are located downstream of the location where the reductant is introduced. In this embodiment, the auxiliary blades 1108 generate a first swirl in a first direction and the main blade 310 and/or the complementary blade 1100 generate a second swirl in a second direction, which may be the same as the first direction (e.g., co-swirl, etc.), or opposite the first direction (e.g., counter-swirl, etc.). Rather than restricting the exhaust flow in a single path to create a swirl, the auxiliary vanes 1108 provide a number of openings between adjacent auxiliary vanes 1108 such that each auxiliary vane 1108 independently swirls the exhaust and such that the auxiliary vanes 1108 collectively form a swirl in the exhaust.

The main blade 310 and/or the auxiliary blade 1108 may be constructed (e.g., produced, manufactured, etc.) using sheet metal (e.g., aluminum sheet, steel sheet, etc.) in a variety of applications. For example, the main blade 310 and/or the auxiliary blade 1108 may be configured by a stamping, punching, laser cutting, water jet cutting, and/or welding operation.

Fig. 12B shows a cross-sectional view of a multi-stage mixer 200 having an auxiliary mixer 1106 comprising complementary vanes 1100 and a second flow device 208 comprising a plurality of second flow device vanes 1200. It should be appreciated that the second flow device vane 1200 shown and described with reference to fig. 12B may be included in any of the embodiments of the multistage mixer 200 discussed herein.

The second flow device vane 1200 may be similar to or different from the main vane 310. Similar to the complementary blade 1100 and the auxiliary blade 1108, the second flow device blade 1200 may be configured to generate a swirl (e.g., co-swirl, anti-swirl, etc.) that is separate from the swirl generated by the main blade 310, the complementary blade 1100, and/or the auxiliary blade 1108. In this manner, the second flow device vane 1200 may be used to increase or decrease the total swirl of exhaust gas and coolant. In the embodiment shown in FIG. 12B, the complementary vane 1100 and the second flow device vane 1200 are located downstream of the location where reductant is introduced. In this embodiment, the complementary vanes 1100 generate a first swirl in a first direction and the second flow device vanes 1200 generate a second swirl in a second direction, which may be the same as the first direction (e.g., co-swirl, etc.) or opposite the first direction (e.g., counter-swirl, etc.).

Fig. 13 shows a cross-sectional view of a multistage mixer 200 with a first flow device 206 and an auxiliary mixer 1106. Although not shown in fig. 13, it should be appreciated that the multi-stage mixer 200 may include an exhaust guide 307. The auxiliary mixer 1106 is located upstream of the exhaust gas directing orifice 306 and the first flow device 206 is located downstream of the exhaust gas directing orifice 306. The auxiliary mixer 1106 is used to generate a swirling flow of the exhaust gas within the first flow device 206 downstream of the auxiliary mixer 1106. The swirling flow created by the auxiliary mixer 1106 aids in the distribution of reductant in the exhaust gas between the auxiliary mixer 1106 and the main vane 310 such that the reductant is substantially uniformly distributed within the exhaust gas as the exhaust gas encounters the main vane 310. In addition, the swirling flow created by the auxiliary mixer 1106 creates relatively large shear at the venturi body 302 (e.g., portions of the venturi body 302 between the auxiliary vanes 1108 and the main vanes 310, etc.) to reduce film formation, thereby reducing the accumulation of venturi deposits along the venturi body 302. The main vane 310 is used to impart swirl on the exhaust gas and entrained reductant downstream of the first flow device 206. This swirling results in the exhaust gas being relatively uniform (e.g., in terms of reductant components, etc.) downstream of the first flow device 206, such as at the multi-stage mixer outlet 204 (e.g., near the inlet of the SCR catalyst 106).

The venturi body 302 is defined by a body central axis 1300. The venturi body 302 is centered about the body central axis 1300 (e.g., the centroid of the venturi body 302 coincides therewith, etc.). The auxiliary blades 1108 and the main blade 310 are also centered on the main body central axis 1300. The first support flange 304 is defined by a mixer central shaft 1302. In addition to the benefits of the auxiliary vanes 1108 and the main vanes 310 mixing the reducing agent in the exhaust, the first support flange 304 is configured such that the main body central axis 1300 is offset radially by h _r Offset from mixer central axis 1302. Radial offset h _r Causing any accumulation of reductant on the venturi body 302 (e.g., uneven distribution of reductant in the exhaust gas within the first flow device 206, etc.) to be substantially redistributed into the exhaust gas downstream of the first flow device 206. While the body center axis 1300 is offset from the mixer center axis 1302 toward the port 216 by a radial offset h in fig. 13 _r . It will be appreciated that the body center shaft 1300 may be radially offset h from the mixer center shaft 1302 _r Offset from port 216, or offset from mixer central shaft 1302 by radial offset h toward venturi body 302 (e.g., orthogonal to port 216, etc.) _r 。

The venturi body 302 has a body inlet 1304 and a body outlet 1306. The inlet having a diameter d _v The outlet has a diameter less than d _v Diameter d of (2) _s . Diameter d _v And diameter d _s Are all smaller than the diameter D of the multistage mixer 200 ₀ . In various embodiments, the multistage mixer 200 and the first flow device 206 are configured such that

0.4D ₀ ≤d _v ≤0.9D ₀ (9)

0.7d _v ≤d _s ≤d _v (10)

0≤h _r ≤0.1D ₀ (II)

In various embodiments, the first support flange 304 does not protrude into the venturi body 302 (e.g., the first support flange 304 defines an abutment with the venturi body 302 and has a diameter equal to the diameter d) _s Orifices of (c), etc.).

In various embodiments, the funnel-shaped edge 300 protrudes radially from the body inlet 1304 a distance h toward the multi-stage mixer 200 _i . In various embodiments, the first flow device 206 is configured such that

0≤h _i ≤0.1d _v (12)

By varying the distance h _i The flow of exhaust gas into the first flow device 206 and/or the exhaust guide orifice 306 may be optimized.

The reductant flows from port 216 through exhaust guide orifice 306. The exhaust guide aperture 306 is generally circular and is defined by a diameter d _e And (3) limiting. In various embodiments, the first flow device 206 is configured such that

Wherein the method comprises the steps of

5°≤δ≤20° (14)

Where δ is a margin selected based on the configuration of the first flow device 206, and where α is the spray angle of the nozzle 1000. In some embodiments, the exhaust guide aperture 306 is oval. In these embodiments, the diameter de may be the major axis of the exhaust guide aperture 306 (e.g., as opposed to the minor axis, etc.).

The first flow means 206 is also defined by the spacing Lm between the trailing edge of the auxiliary blade 1108 and the trailing edge of the main blade 310. In various embodiments, the first flow device 206 is configured such that

The venturi body 302 includes a shroud 1308. It should be appreciated that the shroud 1308 shown and described with reference to FIG. 13 may be included in any of the embodiments of the multi-stage mixer 200 discussed herein.

The shroud 1308 defines the downstream end of the venturi body 302 and is therefore defined by a diameter ds. In various embodiments, the shield 1308 is cylindrical or conical in shape (e.g., frustoconical, etc.). The shroud 1308 may help reduce exhaust stratification caused by centrifugal forces generated by the primary mixer 309. Additionally, the shroud 1308 may provide structural support for the primary mixer 309, such as when the primary blades 310, except for the primary blade center hub 313, are attached to the shroud 1308 (e.g., such that the primary blades 310 conform to the shroud 1308, etc.). When the main blades 310 are attached to the shroud 1308, the main blades 310 may provide a more direct swirl (e.g., along a target trajectory, etc.) by removing the leakage path, thereby improving mixing performance (e.g., the ability of the main mixer 309 to mix reductant and exhaust gas, etc.) and reducing accumulation of deposits downstream of the main mixer 309 (e.g., in the shroud 1308, exhaust components downstream of the multi-stage mixer 200, etc.). Further, the shroud 1308 substantially prevents leakage flow and liquid film build-up and mitigates the formation of deposits within the first flow device 206 (e.g., on the venturi body 302, etc.) and/or the multi-stage mixer 200. The shroud 1308 is defined by an angle Φ relative to an axis parallel to the body center axis 1300 and the mixer center axis 1302. In various embodiments, the first flow device 206 is configured such that

Φ≤50° (16)

In various embodiments, the first flow device 206 is configured such that

Wherein L is _s Is the length of the shield 1308. Wherein the shield 1308 is cylindrical, diameter d _s Equal to diameter d _v And

0.02d _v ≤L _s ≤0.25d _v (18)

in some embodiments, at least one flow device of multi-stage mixer 200 is angled with respect to mixer central axis 1302. For example, the first flow device 206 may be configured such that the body center shaft 1300 is tilted upward (e.g., at a positive angle relative thereto, etc.) from the mixer center shaft 1302, or such that the body center shaft 1300 is tilted downward (e.g., at a negative angle relative thereto) from the mixer center shaft 1302.

Fig. 14 shows a modification of the first flow device 206 in fig. 13. In fig. 14, the auxiliary vane 1108 is shown separated from the venturi body 302 by a gap g. In various embodiments, the first flow device 206 is configured such that

0≤g≤0.15d _v (19)

The gap g may mitigate accumulation of reductant deposits on the venturi body 302. The gap g is used to create a substantially axial flow of exhaust gas directed along the venturi body 302 (e.g., on an inner surface of the venturi body 302, etc.). In this way, the gap g may balance the flow of exhaust gas through the auxiliary vane 1108 (e.g., primary tangential flow, etc.) with the axial flow described above and the flow of exhaust gas around the first flow device 206. Instead of, or in addition to, gap g, auxiliary vane 1108 may include a slot (e.g., a thin groove) or hole through which exhaust gas may flow. For example, each auxiliary vane 1108 may include a slot adjacent to an outermost edge of the auxiliary vane 1108. In this example, exhaust gas may flow through the slot and approach the slot near the venturi body 302, providing similar benefits to the gap g.

As shown in FIG. 14, the primary blades 310 are shown in contact with the shroud 1308 such that there is no gap between at least a portion of each primary blade 310 and the shroud 1308. In the exemplary embodiment, a tip (e.g., a most radially outward surface, etc.) of each main blade 310 is welded (e.g., fused, etc.) to shroud 1308.

In some embodiments, the main blade 310 may be separated from the shroud 1308 by a gap gv. In various embodiments, the first flow device 206 is configured such that

0≤g _v ≤0.15d _v (20)

The gap gv may mitigate accumulation of reductant droplets on the shroud 1308. Gap gv is used to create edge guardThe shroud 1308 directs a substantially axial flow of exhaust (e.g., on an inner surface of the shroud 1308, etc.). Instead of the gap g _v Or in addition to gap g _v The main vane 310 may include slots (e.g., thin slots) or holes through which exhaust gas may flow. For example, each main blade 310 may include a slot adjacent to an outermost edge of the main blade 310. In this example, exhaust gas may flow through the slots and approach the slots near the shroud 1308, providing similar benefits to the gap g.

In some embodiments, the tip of each auxiliary vane 1108 is attached (e.g., welded, coupled, etc.) to the venturi body 302 (e.g., such that the auxiliary vanes 1108 conform to the venturi body 302, etc.). When the auxiliary vane 1108 is attached to the venturi body 302, the auxiliary vane 1108 may provide a more direct swirling flow (e.g., along a target trajectory, etc.) by removing the leakage path, thereby improving mixing performance (e.g., the ability of the auxiliary mixer 1106 to mix reductant and exhaust gas, etc.) and reducing accumulation of deposits downstream of the auxiliary mixer 1106 (e.g., in the venturi body 302, on the main mixer 309, in an exhaust component downstream of the multi-stage mixer 200, etc.). In fig. 13, the auxiliary vanes 1108 are shown in contact with the venturi body 302 such that there is no gap between at least a portion of each auxiliary vane 1108 and the venturi body 302.

Each auxiliary blade 1108 is defined by an auxiliary blade angle relative to an auxiliary blade center hub central axis of the auxiliary blade center hub 1109 of the auxiliary blade 1108.

Similarly, the main blade angle of each main blade 310 is defined relative to the main blade center hub central axis of the main blade center hub 313. The auxiliary blade angle of each auxiliary blade 1108 may be different from the auxiliary blade angle in any other auxiliary blade 1108. In various embodiments, the auxiliary blade angle of each auxiliary blade 1108 is between 45 ° and 90 ° (inclusive) with respect to the main blade center hub central axis of the main blade center hub 313, and the main blade angle of the main blade 310 is between 45 ° and 90 ° (inclusive). The auxiliary vane angle of each auxiliary vane 1108 may be selected such that the first flow device 206 is suitable for the target application. Similarly, the main blade angle of each main blade 310 may be selected such that the first flow device 206 is customized for the target application. The auxiliary mixer 1106 may be configured such that the auxiliary blades 1108 are symmetrically or asymmetrically disposed about the auxiliary blade center hub 1109.

The auxiliary blade angle may be different for each auxiliary blade 1108, and the main blade angle may be different from each main blade 310. The auxiliary vane angle of each auxiliary vane 1108 and the main vane angle of each main vane 310 may be selected so as to create an asymmetric swirl of the exhaust gas to direct the flow of the exhaust gas (e.g., toward a target location in the multi-stage mixer 200, etc.) to more evenly distribute the reductant within the exhaust gas and reduce deposits within the first flow device 206 and/or the multi-stage mixer 200 (e.g., on the venturi body 302, etc.).

Fig. 15 shows a first flow device 206 with a main mixer 309, the main mixer 309 having six main blades 310, wherein four main blades 310 each have a first blade angle and two main blades 310 have a second blade angle that is larger than the first blade angle. Fig. 16 shows a main vane 310 of the first flow device 206 of fig. 15.

Fig. 17 shows a first flow device 206 with a main mixer 309, the main mixer 309 having six main blades 310, wherein four main blades 310 each have a first blade angle not equal to 45 degrees, such that four main blades 310 are open, and two main blades 310 have a second blade angle equal to 90 degrees, such that two main blades 310 are closed, thereby forming a combined main blade 1700 comprising three main blades 310. Instead of referring to the main blades 310 as having a 45 blade angle, the main mixer 309 may simply be referred to as having three main blades 310 and one combined main blade 1700.

FIG. 18A illustrates a composite main blade 1700 in one embodiment. The composite main blade 1700 may be formed in various ways. In various embodiments, the composite main blade 1700 is formed from a large main blade 310 that is folded flat (e.g., 90 °, etc.). In these embodiments, the large main blade 310 may be twice the size of the other main blades 310. In other embodiments, the composite main blade 1700 is formed from a first adjacent main blade 1800 and a second adjacent main blade 1802. In these embodiments, the first adjacent master blade 1800 and the second adjacent master blade 1802 are each folded flat, and then the first adjacent master blade 1800 and the second adjacent master blade 1802 are either directly connected (e.g., each adjacent edge of the first adjacent master blade 1800 and the second adjacent master blade 1802 are attached together, etc.) or indirectly connected (e.g., a span member is attached to each of the first adjacent master blade 1800 and the second adjacent master blade 1802, etc.).

Fig. 18B and 18C illustrate a composite main blade 1700 formed from a first adjacent main blade 1800, a second adjacent main blade 1802, and a third adjacent main blade 1804. In these embodiments, the first adjacent primary blade 1800, the second adjacent primary blade 1802, and the third adjacent primary blade 1804 need not be curved flat and may have blade angles.

In fig. 18B, a first adjacent master blade 1800 is coupled to a first span member 1806, the first span member 1806 being coupled to a second adjacent master blade 1802. A first span member 1806 may be attached to the first adjacent main vane 1800 to close and prevent exhaust gas from passing therebetween. Similarly, a first span member 1806 may be connected to a second adjacent primary vane 1802 to close and prevent exhaust gas from passing therebetween. The first adjacent master vane 1800 is also coupled to a second span member 1808, the second span member 1808 being coupled to the third adjacent master vane 1804. A second span member 1808 may be attached to the first adjacent main vane 1800 to close and prevent exhaust gas from passing therebetween. Similarly, a second span member 1808 may be connected to the third adjacent main vane 1804 to close and prevent exhaust gas from passing therebetween.

In fig. 18C, a first aperture 1810 is incorporated into a first span member 1806 and a second aperture 1812 is incorporated into a second span member 1808. The first and second apertures 1810, 1812 are configured to facilitate the passage of exhaust gas therethrough. In this way, the first and second holes 1810, 1812 may slow the formation of a relatively high pressure region upstream of the primary mixer 309. It should be appreciated that the composite master blade 1700 shown and described with reference to fig. 17-18C may be included in any of the embodiments of the multi-stage mixer 200 discussed herein.

Fig. 19 illustrates the flow of exhaust gas within the multi-stage mixer 200 and illustrates how the exhaust gas may operate when encountering the first flow device 206. The exhaust upstream of the first flow device 206 is divided into a main flow 1900 (e.g., venturi flow, swirl, etc.) and a bypass flow 1902 (e.g., auxiliary flow of exhaust, etc.). Primary flow 1900 is provided into first flow device 206 (e.g., primary flow 1900 funnels into venturi body 302 via funnel rim 300, etc.).

In some embodiments, bypass flow 1902 is 5-40% (inclusive) of the sum (e.g., total flow, etc.) of bypass flow 1902 and primary flow 1900. In these embodiments, primary flow 1900 is 60-95% (inclusive) of the sum (e.g., total flow, etc.) of bypass flow 1902 and primary flow 1900. Thus, where multi-stage mixer 200 includes six auxiliary vanes 1108, each gap between adjacent auxiliary vanes 1108 receives 6-16% (inclusive) of the sum (e.g., total flow, etc.) of bypass flow 1902 and main flow 1900. Similarly, where multi-stage mixer 200 does not include auxiliary mixer 1106 and includes six main blades 310, each gap between adjacent main blades 310 receives 6-16% (inclusive) of the sum (e.g., total flow, etc.) of bypass flow 1902 and main flow 1900.

Primary flow 1900 and bypass flow 1902 define a flow split. Flow split is the ratio of bypass 1902 to primary flow 1900, expressed as a percentage of primary flow 1900. The split being of diameter d _v Diameter d _e And distance h _i Is a function of (2). By varying the flow split, a target mixing performance optimization of the first flow device 206 (e.g., based on computational fluid dynamics analysis, etc.), a target deposit formation (e.g., a target amount of deposit formed during a target cycle time), and a target pressure drop (e.g., a comparison of the exhaust pressure upstream of the first flow device 206 with the pressure of the exhaust pressure downstream of the first flow device 206, etc.) may be performed such that the first flow device 206 may be tailored for a target application. In various embodiments, the flow split ratio is between 5% and 70% (inclusive). That is, bypass flow 1902 is between 5% and 70% (inclusive) of primary flow 1900.

The bypass flow 1902 is not immediately provided to the first flow device 206 through the body inlet 1304. Instead, the bypass flow 1902 flows around the funnel edge 300 into the space between the first flow device 206 and the body of the multi-stage mixer 200. Bypass flow 1902 is split into diverted flow 1904 and isolation flow 1906. Diverted flow 1904 is mixed with reductant supplied to first flow device 206 through port 216. For example, if the first flow device 206 includes the exhaust guide 307, then a portion of the bypass flow 1902 enters the exhaust guide 307 and flows from the exhaust guide 307 into the venturi body 302 as a diverted flow 1904. The diverted flow 1904 enters the first flow device 206 through the exhaust guide orifice 306. In embodiments where the first flow device 206 does not include the exhaust guide 307, the bypass flow 1902 may enter the venturi body 302 as the diverted flow 1904 passes directly through the exhaust guide orifice 306.

The isolation flow 1906 does not immediately enter the first flow device 206 but encounters the first support flange 304. In various embodiments, the first support flange 304 encloses the multi-stage mixer 200 and the venturi body 302 and does not allow the isolation flow 1906 to pass through the first support flange 304 or around the first support flange 304. In these embodiments, the isolation flow 1906 flows back toward the body inlet 1304. As the isolation flow 1906 flows back toward the body inlet 1304, a portion of the isolation flow 1906 may enter the exhaust guide 307 and flow into the venturi body 302 as a diverted flow 1904. Other portions of isolation flow 1906 may flow through exhaust guide 307 and enter venturi body 302 as primary flow 1900 through body inlet 1304. In other embodiments, the first support flange 304 includes at least one aperture that allows exhaust gas to pass therethrough, thereby allowing at least a portion of the isolation flow 1906 to bypass the body entirely. This portion of isolation flow 1906 will mix with main flow 1900 downstream of body outlet 1306 (e.g., after main flow 1900 combines with diverted flow 1904 and reductant within venturi body 302, etc.).

According to the embodiment shown in FIG. 19, primary flow 1900 is mixed with reductant and diverted flow 1904 by auxiliary vanes 1108, then passes through primary vanes 310, through shroud 1308, and out body outlet 1306.

As shown in fig. 20, which illustrates a view of an upstream face of the first flow device 206, the first flow device 206 includes a second support flange 2000 (e.g., an upstream support flange, etc.). It should be appreciated that the second support flange 2000 shown and described with reference to fig. 20 may be included in any of the embodiments of the multi-stage mixer 200 discussed herein.

The second support flange 2000 is coupled to the first flow device 206 and the multi-stage mixer 200. The second support flange 2000 is disposed upstream of the first support flange 304. In various embodiments, the second support flange 200 is disposed upstream of the exhaust guide 307. The second support flange 2000 facilitates the passage of exhaust gas through the second support flange 2000. In fig. 20, the first support flange 304 is hidden to facilitate viewing of the second support flange 2000.

The second support flange 2000 includes a plurality of second support flange apertures 2001 (e.g., holes, channels, passages, etc.). The bypass flow 1902 traverses the second support flange 2000 through the second support flange aperture 2001. In addition, the isolation flow 1906, after being redirected upstream by the first support flange 304, may pass through the second support flange 2000 through the second support flange orifice 2001 and into the venturi body 302 through the body inlet 1304. In various embodiments, the second support flange 2000 may include one, two, three, four, five, six, or more second support flange apertures 2001.

Each second support flange aperture 2001 is separated from an adjacent second support flange aperture 2001 by a second support flange connector 2002 (e.g., arm, lever, etc.). The second support flange connector 2002 is integrated with the second support flange 2000 and coupled to the multi-stage mixer 200 and the first flow device 206. In one example, the second support flange connector 2002 is coupled to the venturi body 302, while the first support flange 304 is coupled to the shroud 1308. In some embodiments, the second support flange 2000 is coupled to the funnel rim 300 (e.g., the funnel rim 300 is part of the second support flange 2000, etc.).

The second support flange 2000 does not protrude into the body inlet 1304 (e.g., the second support flange 2000 defines an aperture or the like that is contiguous with the venturi body 302 and has a diameter equal to the diameter dv). In various embodiments, the second support flange 2000 includes one, two, three, four, five, six, or more second support flange connectors 2002. In some embodiments, the number of second support flange apertures 2001 is equal to the number of second support flange connectors 2002.

Fig. 21 illustrates a third support flange 2100 (e.g., an upstream support flange, etc.) according to an example embodiment. It should be appreciated that the third support flange 2100 illustrated and described with reference to fig. 21 may be included in any of the embodiments of the multi-stage mixer 200 discussed herein.

The third support flange 2100 has the same function as the second support flange 2000 already described. In various embodiments, the first flow device 206 includes a third support flange 2100 or a second support flange 2000. In some embodiments, the first flow device 206 includes a second support flange 2000 and a third support flange 2100.

The third support flange 2100 may be coupled to the venturi body 302 upstream of the exhaust guide aperture 306, as shown in fig. 21, which illustrates a view of the upstream face of the first flow device 206. The third support flange 2100 may also be coupled to the venturi body 302 downstream of the exhaust guide aperture 306 but upstream of the first support flange 304. The third support flange 2100 may also be coupled to the venturi body 302 upstream of the exhaust guide aperture 306. In some embodiments, the third support flange 2100 is contiguous with the funnel edge 300 (e.g., the funnel edge 300 is part of the third support flange 2100, etc.).

The third support flange 2100 includes a plurality of third support flange apertures 2102 (e.g., holes, channels, passages, etc.). The bypass flow 1902 traverses the third support flange 2100 through the third support flange aperture 2102. In various embodiments, the third support flange 2100 may include one, two, three, four, five, six, or more third support flange apertures 2102.

Each of the third support flange apertures 2102 is separated from an adjacent third support flange aperture 2102 by a third support flange connector 2104 (e.g., arm, rod, etc.). The third support flange connector 2104 is integrated with the third support flange 2100 and is coupled to the multi-stage mixer 200 and the first flow device 206. In one example, the third support flange connector 2104 is coupled to the venturi body 302, while the first support flange 304 is coupled to the shroud 1308. In some embodiments, the third support flange 2100 is coupled to the funnel rim 300 (e.g., the funnel rim 300 is part of the third support flange 2100, etc.).

The third support flange 2100 does not protrude into the body inlet 1304 (e.g., the third support flange 2100 defines an abutment with the venturi body 302 and has a diameter equal to the diameter d _v Orifices of (c), etc.). In various embodiments, the third support flange 2100 includes one, two, three, four, five, six, or more third support flange connectors 2104. In some embodiments, the number of third support flange apertures 2102 is equal to the number of third support flange connectors 2104.

Fig. 22A and 22B illustrate a conduit straight blade mixer 2200 in accordance with an exemplary embodiment. It should be appreciated that the conduit straight blade mixer 2200 shown and described with reference to fig. 22A and 22B may be included in any of the embodiments of the multistage mixer 200 discussed herein.

The duct blade mixer 2200 includes a plurality of duct blade bars 2202, each duct blade bar 2202 coupled to and conforming with a duct blade bar center hub 2206. Rather than forming apertures between any of the conduit blades 2202, any of the conduit blades 2202 and any combination of the conduit blades form conduits therebetween as are formed between adjacent main blades 310. As explained herein, a conduit is a closed channel (e.g., defined on four of six sides, etc.) having a single inlet and a single outlet.

Although not shown, the tip (e.g., outermost edge, etc.) of each conduit straight blade 2202 is coupled to and conforms with the shroud 1308 or the venturi body 302. Trailing edge of one of the duct straightening blades 2202 or of the combined duct straightening blade is along the air flow direction S _t Extends beyond the leading edge of the adjacent one of the duct blade 2202 or the combined duct blade, thereby restricting the flow of exhaust gas in the spanwise direction Sp. Air flow direction S _t Tangential to the tip of the leading edge, while the spanwise direction Sp is perpendicular (e.g., orthogonal, etc.) to the airflow direction St. This spanwise restriction is combined with compliant coupling of the conduit straight blade 2202. Conduit straight blade center hub 2206The shroud 1308 (both restricting flow in the direction of the wall normal) forms a conduit for each of the conduit blades 2202. Each conduit has four sides: the first side is defined by one duct straightening vane 2202 or combination duct straightening vane, the second side is defined by a duct straightening vane center hub 2206, the third side is defined by the shroud 1308 or venturi body 302, and the fourth side is defined by another duct straightening vane 2202 or combination duct straightening vane. Each conduit effectively directs exhaust. In various embodiments, a conduit straight vane mixer 2200 is used in the first flow device 206 in place of the main mixer 309. In other embodiments, the conduit straight blade 2202 is not coupled to the shroud 1308, but rather is connected to and conforms with the venturi body 302. In these embodiments, the conduit straight blade 2202 is instead coupled to the venturi body 302 and conforms to the venturi body 302. In such embodiments, a conduit straight blade mixer 2200 is used instead of or in addition to the auxiliary mixer 1106.

In some embodiments, the catheter straight blade mixer 2200 includes two, three, four, five, six, seven, eight, or more catheter straight blades 2202. Similar to the main blade 310, each of the conduit straight blades 2202 is defined by a blade angle. These blade angles may be varied so that a combined duct blade (not shown) may be formed as described in relation to the combined main blade 1700 above. In some embodiments, the catheter straight blade mixer 2200 includes one, two, three, or more combined catheter blades. In other embodiments, the duct blade mixer 2200 does not include a combined duct blade. In an exemplary embodiment, the duct blade mixer 2200 includes three duct blades 2202 and a combined duct blade.

The conduit straight blade center hub 2206 may be centered on the mixer center shaft 1302 or offset from the mixer center shaft 1302. For example, the catheter straight blade center hub 2206 may be centered on the body center axis 1300 and thus offset radially by h _r Offset from mixer central axis 1302. The duct straightening vane 2202 and/or the combined duct straightening vane may be symmetrically or asymmetrically arranged about the duct straightening vane center hub 2206.

Catheter tubeEach of the straight blades 2202 and the combination conduit straight blade extends over an adjacent conduit straight blade 2202 or the combination conduit straight blade. This distance is seen in FIG. 22A as the extension distance E _sw . Extension distance E _sw Expressed as a percentage of the width in the flow direction St of the individual conduit straight blade 2202 at a given distance from the axis (e.g., body center axis 1300, mixer center axis 1302, etc.), the conduit straight blade center hub 2206 is centered on the axis. In various embodiments, the extension distance E _sw Flow direction S of a single conduit straight blade 2202 at a given distance from the axis _t Between 0% and 75% of the width (inclusive) of the upper, the catheter straight blade center hub 2206 is centered on the shaft.

The duct blade mixer 2200 provides relatively high swirl velocity even at lower blade angles for each duct blade 2202, thereby providing enhanced mixing with a lower pressure drop reductant. Another benefit of the high swirl velocity provided by the duct straightening vane 2202 and the combined duct straightening vane is that the high swirl velocity mitigates the accumulation of sediment downstream of the duct straightening vane mixer 2200 (e.g., along the venturi body 302, along the shroud 1308, etc.).

Each of the duct straightening vane 2202 and the combined duct straightening vane is formed by a flow direction angle α with respect to the shaft _sa Defining, the conduit straight blade center hub 2206 is centered on an axis (e.g., body center shaft 1300, mixer center shaft 1302, etc.). In various embodiments, the flow direction angle α _sa Between 30 ° and 90 ° (inclusive). Each flow direction angle αsa of the duct straightening vane 2202 and the combined duct straightening vane may be selected such that the first flow arrangement 206 is suitable for the target application.

For each duct blade 2202 and/or combined duct blade, the flow direction angle α _sa And a flow direction extending distance E _sw May be different. The flow direction angle alpha of each duct blade 2202 and/or of the combined duct blade may be selected _sa And a flow direction extending distance E _sw To create an asymmetric swirl of the exhaust gas to direct the flow of the exhaust gas (e.g., toward a target location in the multi-stage mixer 200, etc., to more evenly distribute reductant within the exhaust gas, and/or to reduce the first flow device 206)And/or deposits within the multi-stage mixer 200 (e.g., on the venturi body 302, etc.).

The duct blade 2202 and/or the combined duct blade can be constructed using casting (e.g., investment casting, lost foam casting, sand casting, etc.) and/or 3D printing. For example, the duct straight blade mixer 2200 may be printed using a 3D printer by using a file specifying the number of duct straight blades 2202, the number of combined duct straight blades, the flow direction angle α of each of the duct straight blades 2202 and the combined duct straight blades _sa And a flow direction extension E of each of the duct straightening vane 2202 and the combined duct straightening vane _sw 。

Fig. 23 illustrates a curved blade mixer 2300 according to an example embodiment. It should be appreciated that the curved blade mixer 2300 shown and described with reference to fig. 23 may be included in any of the embodiments of the multi-stage mixer 200 discussed herein.

In various embodiments, a curved blade mixer 2300 is used in the first flow device 206 in place of the auxiliary mixer 1106 or the main mixer 309. However, curved blade mixer 2300 may additionally or alternatively be used with other flow devices (e.g., second flow device 208, third flow device 210, fourth flow device 212, etc.).

The curved blade mixer 2300 includes a plurality of curved blades 2302 and a combined curved blade 2304. In some embodiments, curved blade mixer 2300 includes two, three, four, five, six, seven, eight, or more of curved blades 2302. In some embodiments, curved blade mixer 2300 includes one, two, three, or more of combined curved blades 2304. In other embodiments, curved blade mixer 2300 does not include composite curved blade 2304. In the exemplary embodiment, curved blade mixer 2300 includes three curved blades 2302 and a combined curved blade 2304.

Each curved blade 2302 and combined curved blade 2304 is attached to a curved blade center hub 2306, which center hub 2306 is centered on the central axis of the multistage mixer 200. The curved blades 2302 and/or the composite curved blades 2304 may be symmetrical or asymmetrical about the curved blade center hub 2306Symmetrically arranged. Similar to the conduit straight blade 2202, each of the curved blade 2302 and the composite curved blade 2304 may overlap. Each bending blade 2302 and composite bending blade 2304 extends the extension distance E described herein on an adjacent bending blade 2302 or composite bending blade 2304 _sw 。

The curved blades 2302 and the combined curved blades 2304 have a curved or streamlined shape that reduces the pressure drop of the exhaust gas and facilitates a more even distribution of flow downstream of the curved blade mixer 2300, for example, along the central axis of the curved blade mixer 2300.

Each curved blade 2302 is defined by a curved blade angle α relative to a curved blade center hub central axis of the curved blade center hub 2306 _cv And (3) limiting. Similarly, the composite curved blade 2304 may be defined by a curved blade angle α relative to a curved blade center hub central axis of the curved blade center hub 2306 _cv And (3) limiting. Due to the bending characteristics of the bending blade 2302 and the combined bending blade 2304, the bending blade angle α _cv Is variable. The bending blade angle α of each of the bending blade 2302 and the combined bending blade 2304 _cv Bending blade angle alpha, which may be combined with other bending blades 2302 and other combined bending blades 2304 _cv Different.

The curved blade 2302 and/or the composite curved blade 2304 may be constructed using casting and/or 3D printing. For example, the curved blade mixer 2300 may be printed using a 3D printer by using a file specifying the number of curved blades 2302, the number of combined curved blades 2304, and the curved blade angle α of each of the curved blades 2302 and the combined curved blades 2304 _cv . In various embodiments, the bending blade 2302 and/or the composite bending blade 2304 may be designed to maintain a constant tangential angle at each point along the bending blade 2302 or the composite bending blade 2304 or to minimize aerodynamic drag on the bending blade 2302 or the composite bending blade 2304. In one embodiment, a 3D printed or cast curved blade 2303 may be inserted into the venturi body 302 and welded to the first support flange 304.

Fig. 24 shows a cross-sectional view of curved blade mixer 2300. At the curved blade center hub 2306A curved blade angle alpha at a first position in the vicinity _cv Shown as angle α with respect to the hub central axis of curved blade central hub 2306 _cv1 And a curved blade angle α at a second position near the distal edge of curved blade 2302 _cv The hub central axis with respect to the curved blade central hub 2306 is considered as angle alpha _cv2 . Angle alpha _cv1 Different from (e.g., less than, etc.) angle alpha _cv2 . Based on the curved blade angle α along the curved blade 2302 _cv (e.g. angle alpha _cv1 Angle alpha _cv2 Etc.) calculates an effective curved blade angle alpha relative to a hub central axis of curved blade central hub 2306 _cve . By using a smaller curved blade angle alpha near the curved blade center hub 2306 _cv The pressure drop of the exhaust gas and the possibility of deposit formation are reduced. Similarly, by using a larger curved blade angle α _cv The swirling flow of the exhaust gas downstream of the curved vane mixer 2300 increases. In this manner, the curved blades 2302 and/or the combined curved blades 2304 may be optimized to produce a swirl that balances a target pressure drop through a target uniformity index.

Fig. 25 and 26 illustrate a common center hub 2500. It should be appreciated that the common center hub 2500 shown and described with reference to fig. 25 and 26 may be included in any of the embodiments of the multistage mixer 200 discussed herein.

The common center hub 2500 may be implemented as any other center hub described herein (e.g., the main blade center hub 313, the auxiliary blade center hub 1109, the conduit straight blade center hub 2206, the curved blade center hub 2306, etc.). The common center hub 2500 is formed from a diameter d _gch And length l _gch And (3) limiting. In various embodiments, diameter d is selected _gch So that

0.05d _v ≤d _gch ≤0.5d _v (21)

And select length l _gch So that

0.02d _v ≤l _gch ≤0.5d _v (22)

The common hub 2500 includes a cylindrical portion 2502 and a conical portion 2504. By incorporating the conical portion 2504, the common hub 2500 may facilitate reducing the pressure drop of the exhaust gas by allowing additional flow to the core of the swirl flow (e.g., downstream of the common hub 2500, etc.). The conical portion 2504 is defined by a cone angle. In various embodiments, the cone angle is between 10 ° and 50 ° (inclusive). In various embodiments, the common central hub 2500 is conical or other similar streamlined shape.

In various embodiments, the common hub 2500 includes a plurality of recesses 2506. The grooves 2506 are depressions (e.g., grooves, cutouts, channels, sculptures, etc.) in the common hub 2500. In the exemplary embodiment, recess 2506 is contained within cylindrical portion 2502 and does not extend onto conical portion 2504. In other embodiments, the groove is not contained within the cylindrical portion 2502 and is located on the conical portion 2504.

Each recess 2506 accommodates a common blade 2600. The grooves 2506 receive the common blades 2600 in a consistent manner such that the exhaust flow follows the geometry of the common blades 2600, thereby mitigating exhaust leakage between the common center hub 2500 and the common blades 2600 and providing a relatively high degree of structural durability.

The common blade 2600 may be implemented as any other blade described herein (e.g., the main blade 310, the complementary blade 1100, the auxiliary blade 1108, the conduit straight blade 2202, the composite conduit straight blade, the curved blade 2302, the composite curved blade 2304, etc.), as well as any other blade described herein. Each common blade 2600 may be attached to a common center hub 2500 within a recess 2506. For example, common blade 2600 may be welded to groove 2506.

The recess 2506 allows for faster and more continuous manufacture of the multi-stage mixer apparatus 200. In particular, it is easier for a manufacturer to control (e.g., because such control can be achieved by a precision tool, etc.) the positioning of the common blade 2600 in the groove 2506 and then attaching the common blade 2600 to the groove 2506 than would be possible without the groove 2506. Furthermore, the grooves 2506 may facilitate low cost or rapid manufacturing techniques, such as laser welding, for coupling the common blade 2600 to the common hub 2500.

Fig. 27 shows a first perforated support flange 2700. It should be appreciated that the first perforated support flange 2700 shown and described with reference to fig. 27 may be included in any of the embodiments of the multi-stage mixer 200 discussed herein.

In various embodiments, a first perforated support flange 2700 is used in the first flow device 206 in place of the first support flange 304. However, the first perforated support flange 2700 may additionally or alternatively be used with other flow devices (e.g., the second flow device 208, the third flow device 210, the fourth flow device 212, etc.). Unlike the first support flange 304, the first perforated support flange 2700 is configured to facilitate the passage of exhaust gas through the first perforated support flange 2700, thereby facilitating the bypass of some of the exhaust gas around the venturi body 302.

The first perforated support flange 2700 is shown in fig. 27 in place of the first support flange 304. Thus, the first perforated support flange 2700 is coupled to the venturi body 302 near the main mixer 309. The first perforated support flange 2700 includes at least one first perforation 2702 (e.g., aperture, hole, etc.). Each first aperture 2702 extends through the first aperture support flange 2700 such that exhaust gas may pass through the first aperture support flange 2700 via the first aperture 2702.

The first perforations 2702 serve to reduce the pressure drop of the exhaust gas and promote a more even distribution of flow downstream of the primary mixer 309, e.g., along the central axis of the primary mixer 309. The first perforation 2702 also serves to create a relatively high exhaust shear on the body of the multi-stage mixer 200, thereby mitigating the accumulation of sediment near the multi-stage mixer outlet 204 of the multi-stage mixer 200.

In various embodiments, the first perforated support flange 2700 includes between 1 and 25 (inclusive) of a first perforation 2702. The first through-holes 2702 may be circular, square, hexagonal, pentagonal, or other similar shapes. In various embodiments, each of the first perforations 2702 has a diameter (inclusive) of between 0.1 inches and 1 inch.

The first aperture 2702 is disposed on a lower perimeter 2704 of the first aperture support flange 2700. The lower perimeter 2704 may be an area of the first perforated support flange 2700 below the main mixer 309 (e.g., relative to the ports 216, etc.). However, the first aperture 2702 may additionally or alternatively be located on other areas of the first aperture support flange 2700, such as the top perimeter above the main mixer 309 or the side perimeter to one side of the main mixer 309. In various embodiments, the first perforations 2702 are aligned in concentric arcs around the main mixer 309 (e.g., such that each of the first perforations 2702 is equally spaced apart from the multi-stage mixer 200, etc.).

By varying the size (e.g., diameter, etc.), location, and number of first perforations 2702, first flow device 206 target mixing performance optimization (e.g., based on computational fluid dynamics analysis, etc.), target deposit formation (e.g., a target amount of deposit formed over a target period of time, etc.), target uniformity index, and target pressure drop (e.g., comparing the pressure of exhaust gas upstream of first flow device 206 to the pressure of exhaust gas downstream of first flow device 206, etc.) may be performed such that first flow device 206 may be tailored for a target application.

Fig. 28 shows a second perforated support flange 2800. It should be appreciated that the second perforated support flange 2800 shown and described with reference to fig. 28 may be included in any of the embodiments of the multi-stage mixer 200 discussed herein.

In various embodiments, a second perforated flange 2800 is used in the first flow device 206 in place of the first support flange 304. However, the second perforated support flange 2800 may additionally or alternatively be used with other flow devices (e.g., the second flow device 208, the third flow device 210, the fourth flow device 212, etc.).

A second perforated support flange 2800 is shown in fig. 28 in place of the first support flange 304. Thus, the second perforated support flange 2800 is coupled to the venturi body 302 near the main mixer 309. The second perforated support flange 2800 includes at least one second perforation 2802 (e.g., aperture, hole, etc.). Each second perforation 2802 extends through the second perforation support flange 2800 such that exhaust gas can pass through the second perforation support flange 2800 via the second perforation 2802.

The second perforations 2802 serve to reduce the pressure drop of the exhaust and promote a more even distribution of flow downstream of the primary mixer 309, such as along the central axis of the primary mixer 309. The second perforation 2802 also serves to create a relatively high exhaust shear on the venturi body 302 such that accumulation of deposits on the venturi body 302 is reduced in areas where shear and swirling may otherwise result in deposit formation. In addition, the location of the second perforation 2802 proximate the venturi body 302 allows the venturi body 302 to receive additional heat from the exhaust.

In various embodiments, the second perforated support flange 2800 includes between 1 and 25 (inclusive) second perforations 2802. The second perforation 2802 can be circular, square, hexagonal, pentagonal, or other similar shape. In various embodiments, each of the second perforations 2802 has a diameter between 0.1 inches and 1 inch (inclusive). At least some (e.g., all, etc.) of the second perforations 2802 may be formed by a stamping operation. The stamping operation provides each second perforation 2802 with a corrugated inlet and a flared outlet. Although not shown in fig. 28, each second perforation 2802 can include an airfoil, similar to the sixth flow device blade 908.

The second perforation 2802 is disposed on an edge perimeter 2804 of the second perforation support flange 2800. The edge perimeter 2804 may be the area of the second perforated support flange 2800 to the side of the primary mixer 309 (e.g., relative to the ports 216, etc.). However, the second perforations 2802 may additionally or alternatively be located on other areas of the second perforation support flange 2800, such as the top perimeter above the main mixer 309 or the bottom perimeter of the main mixer 309. In various embodiments, the second perforations 2802 are aligned in concentric arcs around the primary mixer 309 (e.g., such that each of the second perforations 2802 is equally spaced from the multi-stage mixer 200).

By varying the location, size (e.g., diameter, etc.), number of second perforations 2802, a first flow device 206 target mixing performance optimization (e.g., based on computational fluid dynamics analysis, etc.), target deposit formation (e.g., a target amount of deposit formed over a target period of time, etc.), target uniformity index, and target pressure drop (e.g., comparing the pressure of exhaust gas upstream of the first flow device 206 to the pressure of exhaust gas downstream of the first flow device 206, etc.) may be performed such that the first flow device 206 may be tailored for a target application. In various embodiments, the open area of all of the second perforations 2802 is

Where nperf is the number of second perforations 2802 and d _perf Is the diameter of each second perforation 2802. Relation between Aperf and pressure drop, a _perf The relationship between uniformity index is shown in fig. 29, where Atot is the total area of the second perforated support flange 2800.

Fig. 30 shows a third perforated support flange 3000. It should be appreciated that the third perforated support flange 3000 shown and described with reference to fig. 28 may be included in any of the embodiments of the multi-stage mixer 200 discussed herein.

The third perforated support flange 3000 is similar to the second perforated support flange 2800 described herein. In various embodiments, a third orifice flange 3000 is used in the first flow device 206 in place of the first support flange 304. However, the third perforated support flange 3000 may additionally or alternatively be used with other flow devices (e.g., the second flow device 208, the third flow device 210, the fourth flow device 212, etc.). Unlike the first support flange 304, the third perforated support flange 3000 is configured to facilitate the passage of exhaust gas through the third perforated support flange 3000, thereby facilitating the bypass of some of the exhaust gas around the venturi body 302.

A third perforated support flange 3000 is shown in fig. 30 in place of the first support flange 304. Thus, the third perforated support flange 3000 is coupled to the venturi body 302 near the main mixer 309. The third perforated support flange 3000 includes at least one third perforation 3002 (e.g., aperture, hole, etc.). Each third perforation 3002 extends through the third perforation support flange 3000 such that exhaust gas may pass through the third perforation support flange 3000 via the second perforation 2802. The description of the second perforation 2802 previously applies similarly to the third perforation 3002 and the first perforation 2702. In various embodiments, the third perforations 3002 are equally spaced along an arc that spans 300 degrees from 60 degrees with respect to the central axis of the first flow device 206 and/or the multi-stage mixer 200.

Fig. 31 and 32 depict a shroud vane mixer 3100 according to an exemplary embodiment. It should be appreciated that the shroud blade mixer 3100 shown and described with reference to fig. 31-33 may be included in any of the embodiments of the multi-stage mixer 200 discussed herein.

Fig. 31 shows a cross-sectional view of the shroud-blade mixer 3100. In various embodiments, a shroud vane mixer 3100 is used in the first flow device 206 in place of the auxiliary mixer 1106 or the main mixer 309. However, the shroud vane mixer 3100 may additionally or alternatively be used with other flow devices (e.g., the second flow device 208, the third flow device 210, the fourth flow device 212, etc.).

The shroud blade mixer 3100 includes a plurality of shroud blades 3102 and a combined shroud blade 3104. In some embodiments, the shroud blade mixer 3100 includes two, three, four, five, six, seven, eight, or more of the shroud blades 3102. In some embodiments, the shroud blade mixer 3100 includes one, two, three, or more of the combined shroud blades 3104. In other embodiments, the shroud blade mixer 3100 does not include the combined shroud blades 3104. In the exemplary embodiment, shroud blade mixer 3100 includes three shroud blades 3102 and a combined shroud blade 3104.

Each shroud blade 3102 and composite shroud blade 3104 is attached to a shroud blade center hub 3106, which center hub 2306 is centered about the central axis of the multistage mixer 200. The shroud blades 3102 and/or the composite shroud blades 3104 may be symmetrically or asymmetrically arranged about the shroud blade center hub 3106. Similar to the straight duct blade 2202, each shroud blade 3102 and the composite shroud blade 3104 may overlap.

The shroud blade mixer 3100 includes grooves 2908. The groove 2908 is configured to fit around the exhaust guide hole 306 when the shroud vane mixer 3100 is installed in the multi-stage mixer 200.

The shroud blade mixer 3100 combines the functions of the mixer (e.g., auxiliary mixer 1106, main mixer 309, etc.) with the functions of the shroud (e.g., shroud 1308, etc.) in a single component. In this manner, the shroud vane mixer 3100 may reduce the cost (e.g., manufacturing cost, etc.) and manufacturing complexity of the multi-stage mixer 200. In addition, combining the mixer and shroud in a single component, the shroud blade mixer 3100 reduces manufacturing tolerances in the blade angle of the shroud blades 3102, thereby reducing variability between different shroud blade mixers 3100. The thickness of each shroud blade 3102 through the shroud blade 3102 may be constant or variable, for example, vertical along the shroud blade 3102 or horizontal along the shrouded blade 3102. In various embodiments, the shroud blade 3102 has a thickness between 1.5mm and 6mm (inclusive). Similarly, in various embodiments, the edge of each shroud blade 3102 has a radius of between 0.5mm and 3mm (inclusive). The radius may reduce flow separation of the exhaust gas, reduce accumulation of reductant deposits, and reduce stress concentrations on the shroud blades 3102 and/or shroud 1318.

Fig. 33 illustrates a shroud vane mixer 3100 installed in a multi-stage mixer apparatus 200 according to an exemplary embodiment. In this embodiment, the shroud blade center hub 3106 is centered about the body center axis 1300, and the body center axis 1300 is offset from the mixer center axis 1302 by an angle β. As shown in fig. 33, the angle β is a positive angle such that the shroud-blade mixer 3100 is tilted upward within the multi-stage mixer 200. In various embodiments, angle β is between 0 ° and 15 ° (inclusive). In other embodiments, the angle β is negative such that the shrouded blade mixer 3100 is tilted downward within the multistage mixer 200. In various embodiments, angle β is between 0 ° and 15 ° (inclusive). In other embodiments, the shroud-blade mixer 3100 may be tilted to either side, or some combination of the foregoing directions.

Explanation of example embodiments

Although the description contains many specific implementation details, these should not be construed as limitations on the scope of the claims, but rather as descriptions of features specific to particular implementations. Certain features that are described in this specification in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. Furthermore, although features may be described as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

As used herein, the terms "substantially," "about," and similar terms are intended to have a broad meaning, consistent with the ordinary and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. Those skilled in the art who review this disclosure will appreciate that these terms are intended to allow the description and claims of certain features without limiting the scope of such features to the precise numerical ranges provided. Accordingly, these terms should be construed to indicate that insubstantial or insignificant modifications or variations to the described and claimed subject matter are considered to be within the scope of the invention as described in the appended claims.

The terms "coupled," "coupled to" and the like as used herein mean that two components are connected to each other either directly or indirectly. Such a connection may be stationary (e.g., permanent) or movable (e.g., removable or releasable). Such joining may be achieved by the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another and the two members or the two members and any additional intermediate members being attached to one another.

The terms "fluid coupling," "fluid communication," and the like as used herein mean that two components or objects have a passageway formed between the two components or objects, wherein a fluid, such as exhaust gas, water, air, a gaseous reducing agent, gaseous ammonia, and the like, may flow with or without an intermediate component or object. Examples of fluid couplings or arrangements for effecting fluid communication may include pipes, channels, or any other suitable components for enabling fluid flow from one component or object to another. As described herein, "preventing" should be interpreted as potentially allowing for minimal bypass (e.g., less than 1%) of the exhaust gas.

It is important to note that the construction and arrangement of the system as shown in the various exemplary implementations is illustrative only and is not limiting. All changes and modifications that come within the spirit and/or scope of the described embodiments are desired to be protected. It should be understood that some features may not be necessary and that implementations lacking the various features may be contemplated as within the scope of the application, which is defined by the claims that follow. When the language "a portion" is used, the item may include a portion and/or the entire item unless specifically indicated to the contrary.

Claims

1. A multi-stage mixer for an exhaust aftertreatment system, the multi-stage mixer comprising:

a first flow device comprising

A main mixer having a plurality of main blades and a plurality of main blade apertures, each of said main blade apertures being disposed between two of said main blades,

a venturi body, and

a support flange supporting the venturi body within the multistage mixer;

a second flow device comprising a plurality of second flow device orifices, the second flow device being downstream of the main mixer and configured to receive exhaust gas and reductant from the main mixer; and

A third flow device including a plurality of third flow device orifices, the third flow device being downstream of the second flow device and configured to receive the exhaust gas and the reductant from the second flow device.

2. The multistage mixer according to claim 1, wherein:

the second flow device orifices collectively define a first opening area;

the third flow device orifices collectively define a second open area; and

the second flow means and the third flow means are configured such that the second opening area is equal to the first opening area.

3. The multistage mixer according to claim 2, wherein the average area of the third flow device apertures is smaller than the average area of the second flow device apertures.

4. A multistage mixer according to claim 3, wherein the third flow means is configured such that the third flow means orifices are all identical.

5. A multistage mixer according to claim 3, wherein the number of third flow device orifices in the third flow device is greater than the number of second flow device orifices in the second flow device.

6. The multi-stage mixer of claim 5, further comprising a fourth flow device comprising a plurality of fourth flow device orifices, the fourth flow device being located downstream of the third flow device and configured to receive the exhaust gas and the reductant from the third flow device.

7. The multistage mixer according to claim 6, wherein:

the fourth flow device orifices collectively define a third opening area;

the second flow means and the fourth flow means are configured such that the third opening area is equal to the first opening area;

the fourth flow device orifice has an average area that is less than an average area of the third flow device orifice; and

the number of fourth flow device orifices in the fourth flow device is greater than the number of third flow device orifices in the third flow device.

8. The multistage mixer according to claim 5, wherein:

the second flow means is symmetrical; and

the third flow means is symmetrical.

9. The multistage mixer according to claim 5, wherein the second flow device comprises a central orifice having a diameter greater than the diameter of any one of the second flow device orifices.

10. The multistage mixer according to claim 9, wherein the second flow device orifice is disposed about the central orifice.

11. A multistage mixer according to claim 3, wherein the second flow device orifice comprises:

a first set of orifices disposed about a periphery of the second flow device, each of the first set of orifices having a first diameter; and

a second set of orifices disposed within a central region of the second flow device such that the first set of orifices is disposed about the second set of orifices, the second set of orifices having a second diameter that is greater than the first diameter.

12. A multistage mixer according to claim 3, wherein the second flow device orifice comprises:

a first set of orifices disposed about a periphery of the second flow device, each of the first set of orifices having a first diameter;

a second set of orifices disposed within a central region of the second flow device such that the first set of orifices is disposed about the second set of orifices, the second set of orifices having a second diameter that is less than the first diameter; and

The second flow device includes a greater number of the second orifice groups than the first orifice groups.

13. The multi-stage mixer of claim 1, further comprising a dispenser disposed upstream of the first flow device, the dispenser configured to selectively provide the reductant into the exhaust gas upstream of the first flow device.

14. The multistage mixer according to claim 1, wherein:

the support flange supporting the venturi body within the multi-stage mixer such that the venturi body is separated from the multi-stage mixer by the support flange; and

the main vane is located within the venturi body.

15. The multi-stage mixer of claim 14, wherein the support flange includes a plurality of support flange apertures, each of the support flange apertures configured to facilitate passage of the exhaust gas through the support flange.

16. The multistage mixer according to claim 14, wherein:

the inner diameter of the multistage mixer is D ₀ ；

The diameter of the venturi tube main body is D _C The method comprises the steps of carrying out a first treatment on the surface of the And

0.25D ₀ ≤D _C ≤0.9D ₀ 。

17. the multistage mixer according to claim 16, wherein:

Each of said main blades being attached to a main blade center hub;

the diameter of the main blade center hub is D _H The method comprises the steps of carrying out a first treatment on the surface of the And

0.05D _C ≤D _H ≤0.25D _C 。

18. the multistage mixer according to claim 17, wherein:

the venturi body is centered on a central axis; and

the main blade center hub is centered on the center axis.

19. The multistage mixer according to claim 14, wherein:

the venturi body includes a shroud defining a downstream end of the venturi body; and

the shield is conical.

20. The multistage mixer according to claim 1, wherein at least one of the main blades is curved.

21. The multi-stage mixer of claim 1, wherein one of the main blades is positioned to extend over the other of the main blades.

22. The multi-stage mixer of claim 1, further comprising complementary vanes on one of the main vanes, the complementary vanes defining complementary apertures contiguous with one of the main vane apertures.

23. The multi-stage mixer of claim 22 wherein the complementary blades are angled with respect to one of the main blades.

24. The multi-stage mixer of claim 22, wherein the complementary blade abuts an edge of one of the main blades.

25. The multi-stage mixer of claim 22 wherein the complementary blade is located within one of the main blades.

26. The multistage mixer according to claim 1, wherein the first flow device further comprises an auxiliary mixer upstream of the main mixer, the auxiliary mixer comprising a plurality of auxiliary vanes and a plurality of auxiliary vane apertures, each of the auxiliary vane apertures being located between two of the auxiliary vanes.

27. The multistage mixer according to claim 26, wherein:

the main vane is located within the venturi body;

the auxiliary vane is positioned in the venturi body;

each of the auxiliary blades is attached to an auxiliary blade center hub;

the venturi body is centered on a central axis; and

the auxiliary blade center hub is centered on the central axis.

28. The multistage mixer according to claim 27, wherein:

each of said main blades being attached to a main blade center hub; and

The main blade center hub is centered on the center axis.

29. The multistage mixer according to claim 27, wherein:

the shield is conical.

30. The multi-stage mixer of claim 26, further comprising complementary vanes on one of the auxiliary vanes, the complementary vanes defining complementary apertures contiguous with one of the auxiliary vane apertures.

31. The multi-stage mixer of claim 30, wherein the complementary blade is angled with respect to one of the auxiliary blades.

32. The multi-stage mixer of claim 30, wherein the complementary blade abuts an edge of one of the auxiliary blades.

33. The multistage mixer according to claim 30, wherein the complementary blade is located within one of the auxiliary blades.

34. The multi-stage mixer of claim 27, further comprising a dispenser configured to selectively provide the reductant into the exhaust gas upstream of the main mixer.

35. The multistage mixer according to claim 1, wherein:

the support flange supports the venturi body within the multi-stage mixer such that the venturi body is separated from the multi-stage mixer by the support flange, the support flange centered about a mixer central axis that is offset from a body central axis; and

the main vane is located within the venturi body.

36. The multistage mixer according to claim 35, wherein:

each of said main blades being attached to a main blade center hub; and

the main blade center hub is centered on the main body center axis.

37. The multistage mixer according to claim 36, wherein the first flow device further comprises an auxiliary mixer upstream of the main mixer, the auxiliary mixer comprising a plurality of auxiliary vanes and a plurality of auxiliary vane apertures, each of the auxiliary vane apertures being located between two of the auxiliary vanes.

38. The multistage mixer according to claim 37, wherein:

each of the auxiliary blades is attached to an auxiliary blade center hub; and

the auxiliary blade center hub is centered on the main body center axis.

39. The multi-stage mixer of claim 38, further comprising a dispenser configured to selectively provide the reductant into the exhaust gas upstream of the main mixer;

wherein the support flange is configured to deflect the body central axis away from the dispenser from the mixer central axis.

40. The multistage mixer according to claim 35, wherein the deviation is less than or equal to 10% of the inner diameter of the multistage mixer.

41. The multistage mixer according to claim 1, wherein:

the support flange supports the venturi body within the multi-stage mixer such that the venturi body is separated from the multi-stage mixer by the support flange, the support flange centered on a mixer central axis that is inclined relative to the body central axis; and

the main vane is located within the venturi body.

42. The multistage mixer according to claim 1, wherein:

each of the main blades is attached to a main blade center hub having a hub axle; and

the main blade includes:

A first subset of the main blades, each of the first subset of main blades having a first blade angle relative to the hub axle, and

a second subset of the main blades, each of the second subset of main blades having a second blade angle relative to the hub axle, the second blade angle being different from the first blade angle.

43. The multistage mixer according to claim 1, wherein:

the main blade includes:

the first main blade is provided with a first blade,

a second main blade adjacent to and connected to the first main blade, and

a third main blade adjacent to and connected to the second main blade; and

the first, second and third main blades together form a combined main blade.

44. The multistage mixer according to claim 43, wherein:

each of the main blades is attached to a main blade center hub having a hub axle;

the first main blade having a first blade angle relative to the hub axle;

the second main blade having a second blade angle with respect to the hub axle, the second blade angle being different from the first blade angle; and

The third main blade has a third blade angle with respect to the hub axle, the third blade angle being different from the second blade angle.

45. The multi-stage mixer of claim 43, wherein the second main vane includes an aperture configured to facilitate passage of exhaust gas through the second main vane.

46. The multistage mixer according to claim 1, wherein:

the support flange supporting the venturi body within the multi-stage mixer such that the venturi body is separated from the multi-stage mixer by the support flange, the support flange including a plurality of perforations, each of the perforations configured to facilitate the passage of the exhaust gas through the support flange; and

the main vane is located within the venturi body.

47. The multistage mixer according to claim 46, wherein each of said perforations has a diameter between 0.1 inch and 1 inch, inclusive.

48. The multistage mixer according to claim 46, wherein:

the venturi body is centered on a body central axis; and

the perforations are circumferentially disposed about the body central axis.

49. The multistage mixer according to claim 46, wherein:

the shield is conical.

50. The multistage mixer according to claim 46, wherein the perforations are arranged in an arc along the perforated support flange.

51. The multistage mixer according to claim 46, wherein the perforations are disposed along an edge of the perforated support flange.

52. A multi-stage mixer for an exhaust aftertreatment system, the multi-stage mixer comprising:

a first flow device comprising

a venturi body, and

a support flange supporting the venturi body within the multistage mixer;

a second flow device comprising a plurality of second flow device vanes and a plurality of second flow device vane orifices, each second flow device vane orifice disposed between two of the second flow device vanes, the second flow device downstream of the primary mixer and configured to receive exhaust gas and reductant from the primary mixer; and

53. The multi-stage mixer of claim 52 wherein the first flow device further comprises an auxiliary mixer upstream of the main mixer, the auxiliary mixer comprising a plurality of auxiliary vanes and a plurality of auxiliary vane apertures, each auxiliary vane aperture being located between two of the auxiliary vanes.

54. The multi-stage mixer of claim 52, further comprising a dispenser configured to selectively provide the reductant into the exhaust gas upstream of the main mixer.